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2022-11-17 | On universal butterfly and antisymmetric magnetoresistances | Butterfly magnetoresistance (BMR) and antisymmetric magnetoresistance (ASMR)
are about a butterfly-cross curve and a curve with one peak and one valley when
a magnetic field is swept up and down along a fixed direction. Other than the
parallelogram-shaped magnetoresistance-curve (MR-curve) often observed in
magnetic memory devices, BMR and ASMR are two ubiquitous types of MR-curves
observed in diversified magnetic systems, including van der Waals materials,
strongly correlated systems, and traditional magnets. Here, we reveal the
general principles and the picture behind the BMR and the ASMR that do not
depend on the detailed mechanisms of magnetoresistance: 1) The systems exhibit
hysteresis loops, common for most magnetic materials with coercivities. 2) The
magnetoresistance of the magnetic structures in a large positive magnetic field
and in a large negative magnetic field is approximately the same. With the
generalized Ohm's law in magnetic materials, these principles explain why most
BMR appears in the longitudinal resistance measurements and is very rare in the
Hall resistance measurements. Simple toy models, in which the
Landau-Lifshitz-Gilbert equation governs magnetization, are used to demonstrate
the principles and explain the appearance and disappearance of BMR in various
experiments. Our finding provides a simple picture to understand
magnetoresistance-related experiments. | 2211.09369v1 |
2009-03-16 | Interplay between magnetism and superconductivity and appearance of a second superconducting transition in alpha-FeSe at high pressure | We synthesized tetragonal alpha-FeSe by melting a powder mixture of iron and
selenium at high pressure. Subsequent annealing at normal pressure results in
removing traces of hexagonal beta- FeSe, formation of a rather sharp transition
to superconducting state at Tc ~ 7 K, and the appearance of a magnetic
transition near Tm = 120 K. Resistivity and ac-susceptibility were measured on
the annealed sample at hydrostatic pressure up to 4.5 GPa. A magnetic
transition visible in ac-susceptibility shifts down under pressure and the
resistive anomaly typical for a spin density wave (SDW) antiferromagnetic
transition develops near the susceptibility anomaly. Tc determined by the
appearance of a diamagnetic response in susceptibility, increases linearly
under pressure at a rate dTc/dP = 3.5 K/GPa. Below 1.5 GPa, the resistive
superconducting transition is sharp; the width of transition does not change
with pressure; and, Tc determined by a peak in drho/dT increases at a rate ~
3.5 K/GPa. At higher pressure, a giant broadening of the resistive transition
develops. This effect cannot be explained by possible pressure gradients in the
sample and is inherent to alpha-FeSe. The dependences drho(T)/dT show a
signature for a second peak above 3 GPa which is indicative of the appearance
of another superconducting state in alpha-FeSe at high pressure. We argue that
this second superconducting phase coexists with SDW antiferromagnetism in a
partial volume fraction and originates from pairing of charge carriers from
other sheets of the Fermi surface. | 0903.2873v1 |
2022-05-19 | High pressure structural and magneto-transport studies on type-II Dirac semimetal candidate Ir2In8S: Emergence of superconductivity upon decompression | The structural and magneto-transport properties of type-II Dirac semimetal
candidate Ir2In8S have been investigated under high pressure. The ambient
tetragonal structure (P4_2/mnm) is found to be stable up to 7 GPa, above which
the system takes an orthorhombic Pnnm structure, possibly destroying the Dirac
cones due to the loss of the four-fold screw symmetry. In the tetragonal
structure, a gradual suppression of the transverse magneto-resistance and a
rapid change in the magnetic field dependence above 50K suggest possible
T-dependent Fermi surface modification. In the high pressure phase, the
metallic character increases marginally (as evident from the increased RRR
value) accompanied with suppressed magneto-resistance, without emergence of
superconductivity up to 20 GPa and down to 1.4K. Most surprisingly, upon
release of pressure to 0.2 GPa, a sharp resistance drop below 4K is observed,
field varying measurements confirm this as the onset of superconductivity. The
observed changes of the carrier density and mobility in the pressure-released
tetragonal phase indicate electronic structural modification resulting from the
irreversible polyhedral distortion. A simultaneous increase in the residual
resistivity and carrier density upon decompression indicates that an enhanced
impurity scattering play a key role in the emergence of superconductivity in
the tetragonal Ir2In8S, making it an ideal platform to study topological
superconductivity. | 2205.09798v1 |
2022-11-08 | Effective resistivity in relativistic collisionless plasmoid-mediated reconnection | Magnetic reconnection can power spectacular high-energy astrophysical
phenomena by producing non-thermal energy distributions in highly magnetized
regions around compact objects. By means of two-dimensional fully kinetic
particle-in-cell (PIC) simulations we investigate relativistic collisionless
plasmoid-mediated reconnection in magnetically dominated pair plasmas with and
without guide field. In X-points, where diverging flows result in a
non-diagonal thermal pressure tensor, a finite residence time for particles
gives rise to a localized collisionless effective resistivity. Here, for the
first time for relativistic reconnection in a fully developed plasmoid chain we
identify the mechanisms driving the non-ideal electric field using a full Ohm's
law by means of a statistical analysis based on our PIC simulations. We show
that the non-ideal electric field is predominantly driven by gradients of
nongyrotropic thermal pressures. We propose a kinetic physics motivated
non-uniform effective resistivity model, which is negligible on global scales
and becomes significant only locally in X-points, that captures the properties
of collisionless reconnection with the aim of mimicking its essentials in
non-ideal magnetohydrodynamic descriptions. This effective resistivity model
provides a viable opportunity to design physically grounded global models for
reconnection-powered high-energy emission. | 2211.04553v1 |
2023-10-23 | Deep learning denoiser assisted roughness measurements extraction from thin resists with low Signal-to-Noise Ratio(SNR) SEM images: analysis with SMILE | The technological advance of High Numerical Aperture Extreme Ultraviolet
Lithography (High NA EUVL) has opened the gates to extensive researches on
thinner photoresists (below 30nm), necessary for the industrial implementation
of High NA EUVL. Consequently, images from Scanning Electron Microscopy (SEM)
suffer from reduced imaging contrast and low Signal-to-Noise Ratio (SNR),
impacting the measurement of unbiased Line Edge Roughness (uLER) and Line Width
Roughness (uLWR). Thus, the aim of this work is to enhance the SNR of SEM
images by using a Deep Learning denoiser and enable robust roughness extraction
of the thin resist. For this study, we acquired SEM images of Line-Space (L/S)
patterns with a Chemically Amplified Resist (CAR) with different thicknesses
(15nm, 20nm, 25nm, 30nm), underlayers (Spin-On-Glass-SOG, Organic
Underlayer-OUL) and frames of averaging (4, 8, 16, 32, and 64 Fr). After
denoising, a systematic analysis has been carried out on both noisy and
denoised images using an open-source metrology software, SMILE 2.3.2, for
investigating mean CD, SNR improvement factor, biased and unbiased LWR/LER
Power Spectral Density (PSD). Denoised images with lower number of frames
present unaltered Critical Dimensions (CDs), enhanced SNR (especially for low
number of integration frames), and accurate measurements of uLER and uLWR, with
the same accuracy as for noisy images with a consistent higher number of
frames. Therefore, images with a small number of integration frames and with
SNR < 2 can be successfully denoised, and advantageously used in improving
metrology throughput while maintaining reliable roughness measurements for the
thin resist. | 2310.14815v1 |
2023-04-13 | Combining Electron-Phonon and Dynamical Mean-Field Theory Calculations of Correlated Materials: Transport in the Correlated Metal Sr$_2$RuO$_4$ | Electron-electron ($e$-$e$) and electron-phonon ($e$-ph) interactions are
challenging to describe in correlated materials, where their joint effects
govern unconventional transport, phase transitions, and superconductivity. Here
we combine first-principles $e$-ph calculations with dynamical mean field
theory (DMFT) as a step toward a unified description of $e$-$e$ and $e$-ph
interactions in correlated materials. We compute the $e$-ph self-energy using
the DMFT electron Green's function, and combine it with the $e$-$e$ self-energy
from DMFT to obtain a Green's function including both interactions. This
approach captures the renormalization of quasiparticle dispersion and spectral
weight on equal footing. Using our method, we study the $e$-ph and $e$-$e$
contributions to the resistivity and spectral functions in the correlated metal
Sr$_2$RuO$_4$. In this material, our results show that $e$-$e$ interactions
dominate transport and spectral broadening in the temperature range we study
(50$-$310~K), while $e$-ph interactions are relatively weak and account for
only $\sim$10\% of the experimental resistivity. We also compute effective
scattering rates, and find that the $e$-$e$ interactions result in scattering
several times greater than the Planckian value $k_BT$, whereas $e$-ph
interactions are associated with scattering rates lower than $k_BT$. Our work
demonstrates a first-principles approach to combine electron dynamical
correlations from DMFT with $e$-ph interactions in a consistent way, advancing
quantitative studies of correlated materials. | 2304.06771v2 |
2011-07-13 | SDW transition of Fe1 zigzag chains and metamagnetic transition of Fe2 in TaFe$_{1+y}$Te$_3$ | We systematically study the AFM order of Fe1 zigzag chains and spin-flop of
excess Fe2 under high magnetic field H through the susceptibility,
magnetoresistance (MR), Hall effect and specific heat measurements in
high-quality single crystal TaFe$_{1+y}$Te$_3$. These properties suggest that
the high temperature AFM transition of the TaFeTe$_3$ layers should be a
SDW-type AFM order. Below T$_N$, Fe1 antiferromangetic zigzag chains will
induce a inner magnetic field \textbf{H$_{int}$} to interstitial Fe2 and lead
Fe2 also forms an AFM alignment, in which the magnetic coupling strength
between Fe1 and Fe2 is enhanced by decreasing temperature. On the other hand,
the external magnetic field \textbf{H$_{ext}$} inclines to tune interstitial
Fe2 to form FM alignment along \textbf{H$_{ext}$}. When \textbf{H$_{ext}$}
arrives at the "coercive" field H$_C$, which is able to break the coupling
between Fe1 and Fe2, these interstitial Fe2 atoms take a spin-flop from AFM to
FM alignment. The local moment of Fe2 is about 4 $\mu_{\textrm{B}}$/Fe. From
low field ($<$H$_C$) AFM to high field ($>$H$_C$) FM for Fe2, it also induces
sharp drop on resistivity and an anomalous Hall effect. The possible magnetic
structure of TaFe$_{1+y}$Te$_3$ is proposed from the susceptibility and MR. The
properties related to the spin-flop of Fe2 supply a good opportunity to study
the coupling between Fe1 and Fe2 in these TaFe$_{1+y}$Te$_3$ or Fe$_{1+y}$Te
with interstitial Fe2 compounds. | 1107.2561v1 |
2012-05-06 | Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy | Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired
electron spins in solids and liquids to reveal local structure and dynamics;
for example, EPR has elucidated parts of the structure of protein complexes
that have resisted all other techniques in structural biology. EPR can also
probe the interplay of light and electricity in organic solar cells and
light-emitting diodes, and the origin of decoherence in condensed matter, which
is of fundamental importance to the development of quantum information
processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes
more powerful at high magnetic fields and frequencies, and with excitation by
coherent pulses rather than continuous waves. However, the difficulty of
generating sequences of powerful pulses at frequencies above 100 GHz has, until
now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here
we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a
pulsed EPR spectrometer at 240 GHz (8.5 T), providing transformative
enhancements over the alternative, a state-of-the-art ~30 mW solid state
source. Using the UC Santa Barbara FEL as a source, our 240 GHz spectrometer
can rotate spin-1/2 electrons through pi/2 in only 6 ns (vs. 300 ns with the
solid state source). Fourier transform EPR on nitrogen impurities in diamond
demonstrates excitation and detection of EPR lines separated by ~200 MHz.
Decoherence times for spin-1/2 systems as short as 63 ns are measured, enabling
measurement of the decoherence time in a frozen solution of nitroxide
free-radicals at temperatures as high as 190 K. Both FELs and the quasi-optical
technology developed for the spectrometer are scalable to frequencies well in
excess of 1 THz, opening the possibility of high-power pulsed EPR spectroscopy
up to the highest static magnetic fields on earth. | 1205.1186v1 |
2014-02-10 | Development of CMOS pixel sensors for tracking and vertexing in high energy physics experiments | CMOS pixel sensors (CPS) represent a novel technological approach to building
charged particle detectors. CMOS processes allow to integrate a sensing volume
and readout electronics in a single silicon die allowing to build sensors with
a small pixel pitch ($\sim 20 \mu m$) and low material budget ($\sim 0.2-0.3\%
X_0$) per layer. These characteristics make CPS an attractive option for
vertexing and tracking systems of high energy physics experiments. Moreover,
thanks to the mass production industrial CMOS processes used for the
manufacturing of CPS the fabrication construction cost can be significantly
reduced in comparison to more standard semiconductor technologies. However, the
attainable performance level of the CPS in terms of radiation hardness and
readout speed is mostly determined by the fabrication parameters of the CMOS
processes available on the market rather than by the CPS intrinsic potential.
The permanent evolution of commercial CMOS processes towards smaller feature
sizes and high resistivity epitaxial layers leads to the better radiation
hardness and allows the implementation of accelerated readout circuits. The
TowerJazz $0.18 \mu m$ CMOS process being one of the most relevant examples
recently became of interest for several future detector projects. The most
imminent of these project is an upgrade of the Inner Tracking System (ITS) of
the ALICE detector at LHC. It will be followed by the Micro-Vertex Detector
(MVD) of the CBM experiment at FAIR. Other experiments like ILD consider CPS as
one of the viable options for flavour tagging and tracking sub-systems. | 1402.2172v1 |
2020-04-23 | SENSEI: Direct-Detection Results on sub-GeV Dark Matter from a New Skipper-CCD | We present the first direct-detection search for eV-to-GeV dark matter using
a new ~2-gram high-resistivity Skipper-CCD from a dedicated fabrication batch
that was optimized for dark-matter searches. Using 24 days of data acquired in
the MINOS cavern at the Fermi National Accelerator Laboratory, we measure the
lowest rates in silicon detectors of events containing one, two, three, or four
electrons, and achieve world-leading sensitivity for a large range of sub-GeV
dark matter masses. Data taken with different thicknesses of the detector
shield suggest a correlation between the rate of high-energy tracks and the
rate of single-electron events previously classified as "dark current." We
detail key characteristics of the new Skipper-CCDs, which augur well for the
planned construction of the ~100-gram SENSEI experiment at SNOLAB. | 2004.11378v3 |
2018-12-04 | Superconductivity at 250 K in lanthanum hydride under high pressures | The discovery of superconductivity at 203 K in H3S brought attention back to
conventional superconductors whose properties can be described by the
Bardeen-Cooper-Schrieffer (BCS) and the Migdal-Eliashberg theories. These
theories predict that high, and even room temperature superconductivity (RTSC)
is possible in metals possessing certain favorable parameters such as lattice
vibrations at high frequencies. However, these general theories do not suffice
to predict real superconductors. New superconducting materials can be predicted
now with the aid of first principles calculations based on Density Functional
Theory (DFT). In particular, the calculations suggested a new family of
hydrides possessing a clathrate structure, where the host atom (Ca, Y, La) is
at the center of the cage formed by hydrogen atoms. For LaH10 and YH10
superconductivity, with critical temperatures Tc ranging between 240 and 320 K
is predicted at megabar pressures. Here, we report superconductivity with a
record Tc ~ 250 K within the Fm-3m structure of LaH10 at a pressure P ~ 170
GPa. We proved the existence of superconductivity at 250 K through the
observation of zero-resistance, isotope effect, and the decrease of Tc under an
external magnetic field, which suggests an upper critical magnetic field of 120
T at zero-temperature. The pressure dependence of the transition temperatures
Tc (P) has a maximum of 250-252 K at the pressure of about 170 GPa. This leap,
by ~ 50 K, from the previous Tc record of 203 K indicates the real possibility
of achieving RTSC (that is at 273 K) in the near future at high pressures and
the perspective of conventional superconductivity at ambient pressure. | 1812.01561v1 |
2021-09-18 | Microstructural engineering of medium entropy NiCo(CrAl) alloy for enhanced room and high-temperature mechanical properties | This work demonstrates the development of a strong and ductile medium entropy
alloy by employing conventional alloying and thermomechanical processing to
induce partial recrystallization (PR) and precipitation strengthening in the
microstructure. The combined usage of electron microscopy and atom probe
tomography reveals the sequence of microstructural evolution during the
process. First, the cold working of homogenized alloy resulted in a highly
deformed microstructure. On annealing at 700{\deg}C, B2 ordered precipitates
heterogeneously nucleate on the highly misoriented sites. These B2 promotes
particle stimulated nucleation (PSN) of new recrystallized strain-free grains.
The migration of recrystallized grain boundaries leads to discontinuous
precipitation of L12 ordered regions in highly dense lamellae structures.
Atomic-scale compositional analysis reveals a significant amount of Ni confined
to the GB regions between B2 and L12 precipitates, indicating Ni as a
rate-controlling element for coarsening the microstructure. On 20 hours of
annealing, the alloy comprises a composite microstructure of soft
recrystallized and hard non-recrystallized zones, B2 particles at the grain
boundaries (GBs), and coherent L12 precipitates inside the grains. The B2 pins
the GB movement during recrystallization while the latter provides high
strength. The microstructure results in a 0.2% yield stress (YS) value of 1030
MPa with 32% elongation at ambient temperature and retains up to 910 MPa at
670{\deg}C. Also, it shows exceptional microstructural stability at 700 {\deg}C
and resistance to deformation at high temperatures up to 770{\deg}C.
Examination of deformed microstructure reveals excessive twinning, formation of
stacking faults, shearing of L12 precipitates, and accumulation of dislocations
at around the B2 precipitates and GBs attributed to high strain hardening of
the alloy. | 2109.08894v3 |
2022-10-07 | Fast time-domain current measurement for quantum dot charge sensing using a homemade cryogenic transimpedance amplifier | We developed a high-speed and low-noise time-domain current measurement
scheme using a homemade GaAs high-electron-mobility-transistor-based cryogenic
transimpedance amplifier (TIA). The scheme is versatile for broad cryogenic
current measurements, including semiconductor spin-qubit readout, owing to the
TIA's having low input impedance comparable to that of commercial
room-temperature TIAs. The TIA has a broad frequency bandwidth and a low noise
floor, with a trade-off between them governed by the feedback resistance
$R_{FB}$. A lower $R_{FB}$ of 50 k$\Omega$ enables high-speed current
measurement with a -3dB cutoff frequency $f_{-3dB}$ = 28 MHz and noise-floor
$NF = 8.5 \times 10^{-27}$ A$^{2}$/Hz, while a larger $R_{FB}$ of 400 k$\Omega$
provides low-noise measurement with $NF = 1.0 \times 10^{-27}$ A$^{2}$/Hz and
$f_{-3dB}$ = 4.5 MHz. Time-domain measurement of a 2-nA peak-to-peak square
wave, which mimics the output of the standard spin-qubit readout technique via
charge sensing, demonstrates a signal-to-noise ratio (SNR) of 12.7, with the
time resolution of 48 ns, for $R_{FB}$ = 200 k$\Omega$, which compares
favorably with the best-reported values for the radio-frequency (RF)
reflectometry technique. The time resolution can be further improved at the
cost of the SNR (or vice versa) by using an even smaller (larger) $R_{FB}$,
with a further reduction in the noise figure possible by limiting the frequency
band with a low-pass filter. Our scheme is best suited for readout electronics
for cryogenic sensors that require a high time resolution and current
sensitivity and thus provides a solution for various fundamental research and
industrial applications. | 2210.03333v1 |
2001-03-20 | Fully dense MgB_2 superconductor textured by hot deformation | Bulk textured MgB_2 material of nearly full density showing a weak c-axis
alignment of the hexagonal MgB_2 grains parallel to the pressure direction was
obtained by hot deformation of a stoichiometric MgB_2 pellet prepared by a
gas-solid reaction. The texture of the material was verified by comparing the
x-ray diffraction patterns of the hot deformed material with isotropic MgB_2
powder. A small, but distinct anisotropy of the upper critical field up to
Hc2^{a,b}/Hc2^{c}~1.2 depending on degree of texture was found by resistance
and susceptibility measurements. No anisotropy of the critical current density
determined from magnetization measurements was found for the textured material. | 0103408v2 |
2004-11-22 | Quantized Failure Criteria and Indirect Observation for Predicting the Nanoscale Strength of Materials: The Example of the Ultra Nano Crystalline Diamond | In this paper theoretical and statistical/experimental criteria for
determining the nanoscale strength of materials are proposed. In particular,
quantized criteria in fracture mechanics, dynamic fracture mechanics and
fatigue, as well as an experimental indirect observation of the nanoscale
strength, are proposed. The increasing of the dynamic resistance and the role
of a fractal crack surface formation are also rationalized. The analysis shows
that materials can be sensitive to flaws also at nanoscale (as demonstrated for
carbon nanotubes), in contrast to the conclusion of a recently published paper,
and that the surfaces are weaker than the inner parts of a solid by a factor of
about 10%. In addition, the proposed statistical/experimental procedure is
applied for predicting the nanoscale strength of the ultrananocrystalline
diamond (UNCD), an innovative material only recently developed. | 0411556v1 |
2010-08-05 | Evaluation of the acoustic and non-acoustic properties of sound absorbing materials using a three-microphone impedance tube | This paper presents a straightforward application of an indirect method based
on a three-microphone impedance tube setup to determine the non-acoustic
properties of a sound absorbing porous material. First, a three-microphone
impedance tube technique is used to measure some acoustic properties of the
material (i.e., sound absorption coefficient, sound transmission loss,
effective density and effective bulk modulus) regarded here as an equivalent
fluid. Second, an indirect characterization allows one to extract its
non-acoustic properties (i.e., static airflow resistivity, tortuosity, viscous
and thermal characteristic lengths) from the measured effective properties and
the material open porosity. The procedure is applied to four different sound
absorbing materials and results of the characterization are compared with
existing direct and inverse methods. Predictions of the acoustic behavior using
an equivalent fluid model and the found non-acoustic properties are in good
agreement with impedance tube measurements. | 1008.0975v1 |
2011-02-20 | Intrinsic Correlation between Hardness and Elasticity in Polycrystalline Materials and Bulk Metallic Glasses | Though extensively studied, hardness, defined as the resistance of a material
to deformation, still remains a challenging issue for a formal theoretical
description due to its inherent mechanical complexity. The widely applied
Teter's empirical correlation between hardness and shear modulus has been
considered to be not always valid for a large variety of materials. Here,
inspired by the classical work on Pugh's modulus ratio, we develop a
theoretical model which establishes a robust correlation between hardness and
elasticity for a wide class of materials, including bulk metallic glasses, with
results in very good agreement with experiment. The simplified form of our
model also provides an unambiguous theoretical evidence for Teter's empirical
correlation. | 1102.4063v1 |
2014-07-05 | Large-scale BN tunnel barriers for graphene spintronics | We have fabricated graphene spin-valve devices utilizing scalable materials
made from chemical vapor deposition (CVD). Both the spin-transporting graphene
and the tunnel barrier material are CVD-grown. The tunnel barrier is realized
by h-BN, used either as a monolayer or bilayer and placed over the graphene.
Spin transport experiments were performed using ferromagnetic contacts
deposited onto the barrier. We find that spin injection is still greatly
suppressed in devices with a monolayer tunneling barrier due to resistance
mismatch. This is, however, not the case for devices with bilayer barriers. For
those devices, a spin relaxation time of 260 ps intrinsic to the CVD graphene
material is deduced. This time scale is comparable to those reported for
exfoliated graphene, suggesting that this CVD approach is promising for
spintronic applications which require scalable materials. | 1407.1439v1 |
2017-02-16 | Large elastic recovery of zinc dicyanoaurate | We report the mechanical properties of the `giant' negative compressibility
material zinc(II) dicyanoaurate, as determined using a combination of
single-crystal nanoindentation measurements and \emph{ab initio} density
functional theory calculations. While the elastic response of zinc
dicyanoaurate is found to be intermediate to the behaviour of dense and open
framework structures, we discover the material to exhibit a particularly strong
elastic recovery, which is advantageous for a range of practical applications.
We attribute this response to the existence of supramolecular helices that
function as atomic-scale springs, storing mechanical energy during compressive
stress and hence inhibiting plastic deformation. Our results are consistent
with the relationship noted in [Cheng \& Cheng, \textit{Appl. Phys. Lett.},
1998, {\textbf{73}}, 614] between the magnitude of elastic recovery, on the one
hand, and the ratio of material hardness to Young's modulus, on the other hand.
Drawing on comparisons with other metal--organic frameworks containing helical
structure motifs, we suggest helices as an attractive supramolecular motif for
imparting resistance to plastic deformation in the design of functional
materials. | 1702.05145v1 |
2018-06-19 | Hydrodynamic Phonon Transport Perpendicular to Diffuse-Gray Boundaries | In this paper, we examine the application of an ideal phonon-hydrodynamic
material as the heat transfer medium between two non-hydrodynamic contacts with
a finite temperature difference. We use the integral-equation approach to solve
a modified phonon Boltzmann transport equation with the displaced Bose-Einstein
distribution as the equilibrium distribution between two boundaries
perpendicular to the heat transfer direction. When the distance between the
boundaries is smaller than the phonon normal scattering mean free path, our
solution converges to the ballistic limit as expected. In the other limit, we
find that, although the local thermal conductivity in the bulk of the
hydrodynamic material approaches infinity, the thermal boundary resistance at
the hydrodynamic/non-hydrodynamic interfaces becomes dominant. Our study
provides insights to both the steady-state thermal characterization of
phonon-hydrodynamic materials and the practical application of
phonon-hydrodynamic materials for thermal management. | 1806.07345v3 |
2019-08-26 | One-pot synthesis: a simple and fast method to obtain ceramic superconducting materials | The one-pot method focuses on the reduction of the number of steps or
chemical reactions in the synthesis of materials, and it is very appealing in
terms of sustainability. In addition to this point of view, superconductors are
desired materials due to their unusual properties, such as the zero resistivity
and the perfect diamagnetism. One-pot, Thus, in this work, we described the
one-pot synthesis of YBa2Cu3O7-{\delta} superconducting ceramic. In just two
steps and a few hours, a polymer composite solution was prepared, which
originates a powder after burning the polymer out with pure phase and with
superconducting properties better than those produced by other techniques. | 1908.09923v1 |
2018-07-16 | Tailoring Materials for Mottronics: Excess Oxygen Doping of a Prototypical Mott Insulator | The Mott transistor is a paradigm for a new class of electronic
devices---often referred to by the term Mottronics---, which are based on
charge correlations between the electrons. Since correlation-induced insulating
phases of most oxide compounds are usually very robust, new methods have to be
developed to push such materials right to the boundary to the metallic phase in
order to enable the metal-insulator transition to be switched by electric
gating.
Here we demonstrate that thin films of the prototypical Mott insulator
LaTiO$_3$ grown by pulsed laser deposition under oxygen atmosphere are readily
tuned by excess oxygen doping across the line of the band-filling controlled
Mott transition in the electronic phase diagram. The detected insulator to
metal transition is characterized by a strong change in resistivity of several
orders of magnitude. The use of suitable substrates and capping layers to
inhibit oxygen diffusion facilitates full control of the oxygen content and
renders the films stable against exposure to ambient conditions, making
LaTiO$_{3+x}$ a promising functional material for Mottronics devices. | 1807.05724v1 |
2020-11-25 | Reconstructing the thermal phonon transmission coefficient at solid interfaces in the phonon transport equation | The ab initio model for heat propagation is the phonon transport equation, a
Boltzmann-like kinetic equation. When two materials are put side by side, the
heat that propagates from one material to the other experiences thermal
boundary resistance. Mathematically, it is represented by the reflection
coefficient of the phonon transport equation on the interface of the two
materials. This coefficient takes different values at different phonon
frequencies, between different materials. In experiments scientists measure the
surface temperature of one material to infer the reflection coefficient as a
function of phonon frequency. In this article, we formulate this inverse
problem in an optimization framework and apply the stochastic gradient descent
(SGD) method for finding the optimal solution. We furthermore prove the maximum
principle and show the Lipschitz continuity of the Fr\'echet derivative. These
properties allow us to justify the application of SGD in this setup. | 2011.13047v2 |
2023-01-24 | Using Arduino in Physics Experiments:Determining the Speed of Sound in Air | Considering the 21st century skills and the importance of STEM education in
fulfilling these skills, it is clear that the course materials should be
materials that bring students together with technology and attract their
attention, apart from traditional materials. In addition, in terms of the
applicability of these materials, it is very important that the materials are
affordable and easily accessible. In this study two open ended resonance tube,
Computer and speaker for generate sound with different frequencies, Arduino
UNO, AR-054 Sound Sensor, Green LED and 220 ohm resistance were used for
measure the speed of sound in air at room tempature. With the help of sound
sensor, two consecutive harmonic frequency values were determined and the
fundamental frequency was calculated. Using the tube features and the
fundamental frequency value, the speed of sound propagation in the air at room
temperature was calculated as 386.42 m/s. This value is theoretically 346 m/s.
This study, in which the propagation speed of the sound is calculated with very
low cost and coding studies with 12% error margin, is important in terms of
hosting all STEM gains and can be easily applied in classrooms. | 2301.10325v1 |
2023-09-14 | Photo-induced reversible modification of the Curie-Weiss temperature in paramagnetic gadolinium compounds | Gadolinium oxyhydride GdHO is a photochromic material that darkens under
illumination and bleaches back by thermal relaxation. As an inorganic
photochromic material that can be easily deposited by magnetron sputtering,
GdHO has very interesting potential applications as a functional material,
specially for smart glazing applications. However, the underlying reasons
behind the photochromic mechanism-which can be instrumental for the correct
optimisation of GdOH for different applications-are not completely understood.
In this paper, we rely on the well-stablished magnetic properties of Gd$^{3+}$
to shed light on this matter. GdOH thin films present paramagnetic behaviour
similar to other Gd$^{3+}$ compounds such as Gd$_2$O$_3$. Illumination of the
films result in a reversible increase of the Curie-Weiss temperature pointing
to RKKY interactions, which is consistent with the resistivity decrease
observed in the photo-darkened films. | 2309.07978v1 |
2024-01-26 | First-principles Methodology for studying magnetotransport in magnetic materials | Unusual magnetotransport behaviors such as temperature dependent negative
magnetoresistance(MR) and bowtie-shaped MR have puzzled us for a long time.
Although several mechanisms have been proposed to explain them, the absence of
comprehensive quantitative calculations has made these explanations less
convincing. In our work, we introduce a methodology to study the
magnetotransport behaviors in magnetic materials. This approach integrates
anomalous Hall conductivity induced by Berry curvature, with a multi-band
ordinary conductivity tensor, employing a combination of first-principles
calculations and semi-classical Boltzmann transport theory. Our method
incorporates both the temperature dependency of relaxation time and anomalous
Hall conductivity, as well as the field dependency of anomalous Hall
conductivity. We initially test this approach on two-band models and then apply
it to a Weyl semimetal \CSS. The results, which align well with experimental
observations in terms of magnetic field and temperature dependencies,
demonstrate the efficacy of our approach. Additionally, we have investigated
the distinct behaviors of magnetoresistance (MR) and Hall resistivities across
various types of magnetic materials. This methodology provides a comprehensive
and efficient means to understand the underlying mechanisms of the unusual
behaviors observed in magneto-transport measurements in magnetic materials. | 2401.15146v1 |
2024-03-29 | Computational Shape Derivatives in Heat Conduction: An Optimization Approach for Enhanced Thermal Performance | We analyze an optimization problem of the conductivity in a composite
material arising in a heat conduction energy storage problem. The model is
described by the heat equation that specifies the heat exchange between two
types of materials with different conductive properties with Dirichlet-Neumann
boundary conditions on the external part of the domain, and on the interface
characterized by the resisting coefficient between the highly conductive
material and the less conductive material. The main purpose of the paper is to
compute a shape gradient of an optimization functional in order to accurately
determine the optimal location of the conductive material using a classical
shape optimization strategy. We also present some numerical experiments to
illustrate the efficiency of the proposed method. | 2403.20181v1 |
2002-05-30 | Tunability of High-Dielectric-Constant Materials from First Principles | A first-principles method, based on density functional perturbation theory,
is presented for computing the leading order tunability of
high-dielectric-constant materials. | 0205655v1 |
2024-05-28 | On the resistance regular graphs | For a connected graph $G$, its resistance matrix is denoted by $R(G)$. If all
the row(column) sums of $R(G)$ are equal, then $G$ is said to be resistance
regular. In $[13]$, J. Zhou et al. posed the question regarding the existence
of a non-regular resistance regular graph. In this article, we establish that
all resistance regular graphs are regular, thus conclusively answering Zhou's
question by showing that no non-regular resistance regular graph exists. Also,
we compute the resistance energies of some resistance regular graphs.
Furthermore, we determine various bounds for the resistance energy and
resistance spectral radius of $G.$ | 2405.18177v1 |
2005-06-29 | Galaxy formation and cosmic-ray acceleration in a magnetized universe | We study the linear magneto-hydrodynamical behaviour of a Newtonian cosmology
with a viscous magnetized fluid of finite conductivity and generalise the Jeans
instability criterion. The presence of the field favors the anisotropic
collapse of the fluid, which in turn leads to further magnetic amplification
and to an enhanced current-sheet formation in the plane normal to the ambient
magnetic field. When the currents exceed a certain threshold, the resulting
electrostatic turbulence can dramatically amplify the resistivity of the medium
(anomalous resistivity). This could trigger strong electric fields and
subsequently the acceleration of ultra-high energy cosmic rays (UHECRs) during
the formation of protogalactic structures. | 0506742v1 |
1998-10-21 | Large scale instabilities in two-dimensional magnetohydrodynamics | The stability of a sheared magnetic field is analyzed in two-dimensional
magnetohydrodynamics with resistive and viscous dissipation. Using a
multiple-scale analysis, it is shown that at large enough Reynolds numbers the
basic state describing a motionless fluid and a layered magnetic field, becomes
unstable with respect to large scale perturbations. The exact expressions for
eddy-viscosity and eddy-resistivity are derived in the nearby of the critical
point where the instability sets in. In this marginally unstable case the
nonlinear phase of perturbation growth obeys to a Cahn-Hilliard-like dynamics
characterized by coalescence of magnetic islands leading to a final new
equilibrium state. High resolution numerical simulations confirm quantitatively
the predictions of multiscale analysis. | 9810026v1 |
1997-11-19 | Intrinsic resistivity and the SO(5) theory of high-temperature superconductors | The topological structure of the order parameter in Zhang's SO(5) theory of
superconductivity allows for an unusual type of dissipation mechanism via which
current-carrying states can decay. The resistivity due to this mechanism, which
involves orientation rather than amplitude order-parameter fluctuations, is
calculated for the case of a thin superconducting wire. The approach is a
suitably modified version of that pioneered by Langer and Ambegaokar for
conventional superconductors. | 9711193v2 |
1998-05-22 | reentrance effect in normal-metal/superconducting hybrid loops | We have measured the transport properties of two mesoscopic hybrid loops
composed of a normal-metal arm and a superconducting arm. The samples differed
in the transmittance of the normal/superconducting interfaces. While the low
transmittance sample showed monotonic behavior in the low temperature
resistance, magnetoresistance and differential resistance, the high
transmittance sample showed reentrant behavior in all three measurements. This
reentrant behavior is due to coherent Andreev reflection at the
normal/superconducting interfaces. We compare the reentrance effect for the
three different measurements and discuss the results based on the theory of
quasiclassical Green's functions. | 9805298v1 |
1998-12-20 | Comment on "Charged impurity scattering limited low temperature resistivity of low density silicon inversion layers" (Das Sarma and Hwang, cond-mat/9812216) | In a recent preprint cond-mat/9812216, Das Sarma and Hwang propose an
explanation of the sharp decrease in resistivity at low temperatures which has
been attributed to a transition to an unexpected conducting phase in dilute
high-mobility two-dimensional systems at B=0. In this Comment, we examine
whether their model is supported by the available experimental data. | 9812331v1 |
1999-02-24 | Charge Relaxation and Dephasing in Coulomb Coupled Conductors | The dephasing time in coupled mesoscopic conductors is caused by the
fluctuations of the dipolar charge permitted by the long range Coulomb
interaction. We relate the phase breaking time to elementary transport
coefficients which describe the dynamics of this dipole: the capacitance, an
equilibrium charge relaxation resistance and in the presence of transport
through one of the conductors a non-equilibrium charge relaxation resistance.
The discussion is illustrated for a quantum point contact in a high magnetic
field in proximity to a quantum dot. | 9902320v1 |
1999-03-31 | Apparent Metallic Behavior at B = 0 of a two-dimensional electron system in AlAs | We report the observation of metallic-like behavior at low temperatures and
zero magnetic field in two dimensional (2D) electrons in an AlAs quantum well.
At high densities the resistance of the sample decreases with decreasing
temperature, but as the density is reduced the behavior changes to insulating,
with the resistance increasing as the temperature is decreased. The effect is
similar to that observed in 2D electrons in Si-MOSFETs, and in 2D holes in SiGe
and GaAs, and points to the generality of this phenomenon. | 9903443v1 |
1999-04-05 | Spin Degree of Freedom in a Two-Dimensional Electron Liquid | We have investigated correlation between spin polarization and
magnetotransport in a high mobility silicon inversion layer which shows the
metal-insulator transition. Increase in the resistivity in a parallel magnetic
field reaches saturation at the critical field for the full polarization
evaluated from an analysis of low-field Shubnikov-de Haas oscillations. By
rotating the sample at various total strength of the magnetic field, we found
that the normal component of the magnetic field at minima in the diagonal
resistivity increases linearly with the concentration of ``spin-up'' electrons. | 9904058v1 |
1999-06-17 | Systematic Evolution of the Magnetotransport Properties of Bi_{2}Sr_{2-x}La_{x}CuO_{6} with Carrier Concentration | We report that it is possible to obtain a series of high-quality crystals of
La-doped Bi-2201, of which the transport properties have been believed to be
"dirtier" than those of other cuprates. In our crystals, the normal-state
transport properties display behaviors which are in good accord with other
cuprates; for example, in the underdoped region the in-plane resistivity
\rho_{ab} shows the pseudogap feature and in the overdoped region the T
dependence of \rho_{ab} changes to T^n with n > 1. The characteristic
temperatures of the pseudogap deduced from the resistivity and the Hall
coefficient data are presented. | 9906268v1 |
2000-02-08 | Negative Pressure of Anisotropic Compressible Hall States : Implication to Metrology | Pressure, compressibility, and Hall conductance of anisotropic states at
higher Landau levels are computed. Pressure and compressibility become
negative. Hall conductance is unquantized and varies with filling factor. These
facts agree with the recent experimental observations of highly anisotropic
compressible states at higher Landau levels. It is shown, as an implication of
negative pressure, that the quantum Hall effect has extraordinary stability,
that is, Hall resistance is quantized even when the longitudinal resistance
does not vanish. | 0002108v3 |
2000-12-08 | Pressure, Resistance, and Current Activation of Anisotropic Compressible Hall States | Thermodynamic and electric properties of anisotropic compressible Hall states
at higher Landau levels are studied using a mean field theory on the von
Neumann lattice basis. It is shown that resistances agree with the recent
experiments of anisotropic compressible states and the states have negative
pressure. As implications, the collapse phenomena of the integer quantum Hall
effect are discussed. | 0012133v1 |
2001-07-03 | Scaling Behavior of Anomalous Hall Effect and Longitudinal Nonlinear Response in High-Tc Superconductors | Based on existing theoretical model and by considering our longitudinal
nonlinear response function, we derive a nonliear equation in which the mixed
state Hall resistivity can be expressed as an analytical function of magnetic
field, temperature and applied current. This equation enables one to compare
quantitatively the experimental data with theoretical model. We also find some
new scaling relations of the temperature and field dependency of Hall
resistivity. The comparison between our theoretical curves and experimental
data shows a fair agreement. | 0107045v1 |
2001-07-06 | Current-Driven Conformational Changes, Charging and Negative Differential Resistance in Molecular Wires | We introduce a theoretical approach based on scattering theory and total
energy methods that treats transport non-linearities, conformational changes
and charging effects in molecular wires in a unified way. We apply this
approach to molecular wires consisting of chain molecules with different
electronic and structural properties bonded to metal contacts. We show that
non-linear transport in all of these systems can be understood in terms of a
single physical mechanism and predict that negative differential resistance at
high bias should be a generic property of such molecular wires. | 0107147v1 |
2001-07-17 | Analysis of the resistance in p-SiGe over a wide temperature range | The temperature dependence of a system exhibiting a `metal-insulator
transition in two dimensions at zero magnetic field' (MIT) is studied up to
90K. Using a classical scattering model we are able to simulate the
non-monotonic temperature dependence of the resistivity in the metallic high
density regime. We show that the temperature dependence arises from a complex
interplay of metallic and insulating contributions contained in the calculation
of the scattering rate $1/\td(E,T)$, each dominating in a limited temperature
range. | 0107369v1 |
2001-09-27 | Enhanced paramagnetism of the 4d itinerant electrons in the rhodium oxide perovskite SrRhO3 | Polycrystalline rhodium(IV) oxide perovskite SrRhO3 was obtained by
high-pressure synthesis techniques, followed by measurements of the magnetic
susceptibility, electrical resistivity, and specific heat. The title compound
has five 4d-electrons per perovskite unit and shows Fermi-liquid behavior in
its electrical resistivity. The magnetic susceptibility is large [chi(300K)
\~1.1*10^{-3} emu/mol-Rh] and proportional to 1/T^2 (< 380 K), while there is
no magnetic long-range order above 1.8 K. The specific heat measurements
indicate a probable magnetic contribution below ~ 15 K, which is not predicted
by the self-consistent renormalization theory of spin fluctuations for both
antiferro- and ferromagnetic 3D nearly-ordered metals. | 0109522v2 |
2001-12-20 | Fluctuation induced hopping and spin polaron transport | We study the motion of free magnetic polarons in a paramagnetic background of
fluctuating local moments. The polaron can tunnel only to nearby regions of
local moments when these fluctuate into alignment. We propose this fluctuation
induced hopping as a new transport mechanism for the spin polaron. We calculate
the diffusion constant for fluctuation induced hopping from the rate at which
local moments fluctuate into alignment. The electrical resistivity is then
obtained via the Einstein relation. We suggest that the proposed transport
mechanism is relevant in the high temperature phase of the Mn pyrochlore
colossal magneto resistance compounds and Europium hexaboride. | 0112385v1 |
2002-11-27 | Indications of coherence-incoherence crossover in layered transport | For many layered metals the temperature dependence of the interlayer
resistance has a different behavior than the intralayer resistance. In order to
better understand interlayer transport we consider a concrete model which
exhibits this behavior. A small polaron model is used to illustrate how the
interlayer transport is related to the coherence of quasi-particles within the
layers. Explicit results are given for the electron spectral function,
interlayer optical conductivity and the interlayer magnetoresistance. All these
quantities have two contributions: one coherent (dominant at low temperatures)
and one incoherent (dominant at high temperatures). | 0211612v1 |
2002-11-28 | Small polarons and c-axis transport in highly anisotropic metals | Motivated by the anomalous c-axis transport properties of the quasi
two-dimensional metal, $\rm Sr_2 Ru O_4$, and related compounds, we have
studied the interlayer hopping of single electrons that are coupled strongly to
c-axis bosons. We find a c-axis resistivity that reflects the in-plane
electronic scattering in the low and very high temperature limits (relative to
the characteristic temperature of the boson $T_{\rm boson}$). For temperatures
near the $T_{\rm boson}$, a broad maximum in the resistivity can appear for
sufficiently strong electron-boson coupling. This feature may account for the
observed ``metallic to non-metallic crossover'' seen in these layered oxides,
where the boson may be a phonon. | 0211675v1 |
2003-05-01 | Negative differential resistance due to the resonance coupling of a quantum-dot dimer | Electron tunneling through a coupled quantum-dot dimer under a dc-bias is
investigated. We find that a peak in the $I$-$V$ curve appears at low
temperature when two discrete electronic states in the two quantum dots are
aligned with each other -- resonance coupling. This leads to a negative
differential resistance. The peak height and width depend on the dot-dot
coupling. At high temperature, the peak disappears due to thermal smearing
effects. | 0305018v1 |
2003-08-06 | Measuring thermal conductivity in extreme conditions: sub-Kelvin temperatures and high (27 T) magnetic fields | We present a one-heater-two-thermometer set-up for measuring thermal
conductivity and electric resistivity of a bulk sample at low temperatures down
to 0.1 K and in magnetic fields up to 27 Tesla. The design overcomes the
difficulties emerging in the context of large water-cooled resistive magnets. | 0308106v1 |
2003-09-29 | Fluxon dynamics by microwave surface resistance measurements in MgB2 | Field-induced variations of the microwave surface resistance, Rs(H), have
been investigated in high-density ceramic MgB2. At low temperatures, several
peculiarities of the Rs(H) curves cannot be justified in the framework of
models reported in the literature. We suggest that they are ascribable to the
unconventional vortex structure in MgB2, related to the presence of two gaps.
On the contrary, the results near Tc can be accounted for by the Coffey and
Clem model, with fluxons moving in the flux-flow regime, provided that the
anisotropy of the upper critical field is taken into due account. | 0309654v1 |
2003-10-20 | Evidence for a quantum phase transition in the electron-doped cuprate Pr2-xCexCuO4+d from Hall and resistivity measurements | The doping and temperature dependence of the Hall coefficient, RH, and
ab-plane resistivity in the normal state down to 350mK is reported for oriented
films of the electron-doped high-Tc superconductor Pr2-xCexCuO4+d. The doping
dependence of b (r=r0+AT^b) and R_sub_H (at 350 mK) suggest a quantum phase
transition at a critical doping near x=0.165. | 0310475v2 |
2004-01-15 | Plasmon assisted transport through disordered array of quantum wires | Phononless plasmon assisted thermally activated transport through a long
disordered array of finite length quantum wires is investigated analytically.
Generically strong electron plasmon interaction in quantum wires results in a
qualitative change of the temperature dependence of thermally activated
resistance in comparison to phonon assisted transport. At high temperatures,
the thermally activated resistance is determined by the Luttinger liquid
interaction parameter of the wires. | 0401274v2 |
2004-01-26 | Vanishing Hall Resistance at High Magnetic Field in a Double Layer Two-Dimensional Electron System | At total Landau level filling factor $\nu_{tot}=1$ a double layer
two-dimensional electron system with small interlayer separation supports a
collective state possessing spontaneous interlayer phase coherence. This state
exhibits the quantized Hall effect when equal electrical currents flow in
parallel through the two layers. In contrast, if the currents in the two layers
are equal, but oppositely directed, both the longitudinal and Hall resistances
of each layer vanish in the low temperature limit. This finding supports the
prediction that the ground state at $\nu_{tot}=1$ is an excitonic superfluid. | 0401521v1 |
2004-07-06 | Spin characterization and control over the regime of radiation-induced zero-resistance states | Over the regime of the radiation-induced zero-resistance states and
associated oscillatory magnetoresistance, we propose a low magnetic field
analog of quantum-Hall-limit techniques for the electrical detection of
electron spin- and nuclear magnetic- resonance, dynamical nuclear polarization
via electron spin resonance, and electrical characterization of the nuclear
spin polarization via the Overhauser shift. In addition, beats observed in the
radiation-induced oscillatory-magnetoresistance are developed into a method to
measure and control the zero-field spin splitting due to the Bychkov-Rashba and
bulk inversion asymmetry terms in the high mobility GaAs/AlGaAs system. | 0407143v1 |
2004-08-03 | Electrical resistivity and tunneling anomalies in CeCuAs2 | The compound CeCuAs2 is found to exhibit negative temperature (T) coefficient
of electrical resistivity (rho) under ambient pressure conditions in the entire
T-range of investigation (45 mK to 300 K), even in the presence of high
magnetic fields. Preliminary tunneling spectroscopic measurements indicate the
existence of a psuedo-gap at least at low temperatures, thereby implying that
this compound could be classified as a Kondo semi-conductor, though rho(T)
interestingly is not found to be of an activated type. | 0408060v1 |
2005-01-05 | Radiation-induced zero-resistance states with resolved Landau levels | The microwave-photoexcited high mobility GaAs/AlGaAs two-dimensional electron
system exhibits an oscillatory-magnetoresistance with vanishing resistance in
the vicinity of magnetic fields $B = [4/(4j+1)] B_{f}$, where $B_{f} =
2\pi\textit{f}m^{*}/e$, m$^{*}$ is an the effective mass, e is the charge,
\textit{f} is the microwave frequency, and $j$ =1,2,3... Here, we report
transport with well-resolved Landau levels, and some transmission
characteristics. | 0501091v1 |
2005-01-21 | Metallic behavior in Si/SiGe 2D electron systems | We calculate the temperature, density, and parallel magnetic field dependence
of low temperature electronic resistivity in 2D high-mobility Si/SiGe quantum
structures, assuming the conductivity limiting mechanism to be carrier
scattering by screened random charged Coulombic impurity centers. We obtain
comprehensive agreement with existing experimental transport data, compellingly
establishing that the observed 2D metallic behavior in low-density Si/SiGe
systems arises from the peculiar nature of 2D screening of long-range impurity
disorder. In particular, our theory correctly predicts the experimentally
observed metallic temperature dependence of 2D resistivity in the fully
spin-polarized system. | 0501531v1 |
2005-05-10 | Variable resistance at the boundary between semimetal and excitonic insulator | We solve the two-band model for the transport across a junction between a
semimetal and an excitonic insulator. We analyze the current in terms of two
competing terms associated with neutral excitons and charged carriers,
respectively. We find a high value for the interface resistance, extremely
sensitive to the junction transparency. We explore favorable systems for
experimental confirmation. | 0505247v1 |
2006-02-18 | Anomalous Flux Pinning in ?-Pyrochlore Oxide Superconductor KOs2O6 | The superconducting transition of the ?-pyrochlore oxide KOs2O6 with Tc =
9.60 K is studied by resistivity measurements under various magnetic fields
using a high-quality single crystal. The reentrant behavior of
superconductivity is observed near Tc in low magnetic fields below 2 T. The
recovered resistance probably due to flux flow exhibits an anomalous angle
dependence, indicating that flux pinning is enhanced in magnetic fields along
certain crystallographic directions such as [110], [001] and [112]. It is
suggested that there is an intrinsic pinning mechanism coming from the specific
crystal structure of the ?-pyrochlore oxide. | 0602433v1 |
2006-03-30 | Joule heating induced negative differential resistance in free standing metallic carbon nanotubes | The features of the $IV$ characteristics of metallic carbon nanotubes (m-NTs)
in different experimental setups are studied using semi-classical Boltzmann
transport equation together with the heat dissipation equation to account for
significant thermal effects at high electric bias. Our model predicts that the
shape of the m-NT characteristics is basically controlled by heat removal
mechanisms. In particular we show that the onset of negative differential
resistance in free standing nanotubes finds its origins in strong transport
nonlinearities associated with poor heat removal unlike in substrate-supported
nanotubes. | 0603831v1 |
2007-03-27 | Resistively shunted Josephson junctions: QFT predictions versus MC results | During the last fourteen years several exact results were obtained for the
so-called boundary sine-Gordon model. In the case of a conformal bulk this 2D
boundary quantum field theory describes the universal scaling behavior of the
Caldeira-Leggett model of resistively shunted Josephson junctions. In this
work, we use a recently developed Monte Carlo technique to test some of the
analytical predictions. | 0703712v2 |
1994-02-14 | Fractal Dimension of Gauge-fixing Defects | The fractal dimension $D_f$ of sites resisting Landau or maximal Abelian(MA)
gauge fixing in lattice $SU(3)$ gluodynamics is defined and computed. In Landau
gauge such sites clump into $D_f\sim 1$ clusters in the confining phase. In the
finite temperature phase their dimensionality drops to $D_f < 1$, that is,
clustering seems to dissipate. In contrast, MA gauge resistant sites fail to
exhibit a notable tendency to cluster at any temperature. | 9402009v2 |
2002-07-09 | Body Motion in a Resistive Medium at Temperature T | We consider a macroscopic body propagating in a one-dimensional resistive
medium, consisting of an ideal gas at temperature $T$. For a whole family of
collisions with varying degree of inelasticity, we find an exact expression for
the effective force on the moving body as a function of the body's speed and
the value of the restitution coefficient. At low and high speeds it reduces to
the well-known Stoke's and Newton's law, respectively. | 0207037v1 |
2002-11-29 | Resistive plate chambers for time-of-flight measurements | The applications of Resistive Plate Chambers (RPCs) have recently been
extended by the development of counters with time resolution below 100 ps sigma
for minimum ionising particles. Applications to HEP experiments have already
taken place and many further applications are under study. In this work we
address the operating principles of such counters along with some present
challenges, with emphasis on counter aging. | 0211120v1 |
2007-05-04 | Simultaneous recording of two- and four-probe resistive transitions in doped laser-processed Sr-Ru-O | To confirm previously reported evidence of high-temperature superconductivity
in laser processed Sr-Ru-O, we performed simultaneous two-probe and four-probe
resistive measurements using bar-geometry samples. A superconducting-type
transition with an onset at about 250K was recorded in one of the samples,
consistent with our previously reported measurements in the X-bridge geometry.
Some compositional details of the samples are also provided which were not
known at the time of previous web-publication. | 0705.0641v1 |
2007-07-18 | Synchnonization, zero-resistance states and rotating Wigner crystal | We show that rotational angles of electrons moving in two dimensions (2D) in
a perpendicular magnetic field can be synchronized by an external microwave
field which frequency is close to the Larmor frequency. The synchronization
eliminates collisions between electrons and thus creates a regime with zero
diffusion corresponding to the zero-resistance states observed in experiments
with high mobility 2D electron gas (2DEG). For long range Coulomb interactions
electrons form a rotating hexagonal Wigner crystal. Possible relevance of this
effect for planetary rings is discussed. | 0707.2694v1 |
2007-11-06 | Plasmon phenomena as origin of DC-current induced resistivity oscillations in two-dimensional electron systems | We analyze theoretically the oscillations that the magnetoresistivity of
two-dimensional electron systems present when a high intensity direct current
is applied. In the model presented here we suggest that a plasma wave is
excited in the system producing an oscillating motion of the whole
two-dimensional electron gas at the plasma frequency. This scenario affects
dramatically the way that electrons interact with scatterers giving rise to
oscillations in the longitudinal resistivity. With this theoretical model
experimental results are well reproduced and explained. | 0711.0927v1 |
2008-06-17 | Electrical Resistivity and Specific Heat of EuFe2As2 Single Crystals: Magnetic homologue of SrFe2As2 | We have grown single crystals of EuFe2As2 and investigated its electrical
transport and thermodynamic properties. Electrical resistivity and specific
heat measurements clearly establish the intrinsic nature of magnetic phase
transitions at 20 K and 195 K. While the high temperature phase transition is
associated with the itinerant moment of Fe, the low temperature phase
transition is due to magnetic order of localized Eu-moments. Band structure
calculations point out a very close similarity of the electronic structure with
SrFe2As2. Magnetically, the Eu and Fe2As2 sublattice are nearly de-coupled. | 0806.2876v2 |
2008-08-05 | Suppression of Magnetic Order by Pressure in BaFe2As2 | We performed the dc resistivity and the ZF 75As-NMR measurement of BaFe2As2
under high pressure. The T-P phase diagram of BaFe2As2 determined from
resistivity anomalies and the ZF 75As-NMR clearly revealed that the SDW anomaly
is quite robust against P. | 0808.0718v1 |
2008-10-14 | Magnetic Field Induced Instabilities in Localised Two-Dimensional Electron Systems | We report density dependent instabilities in the localised regime of
mesoscopic two-dimensional electron systems (2DES) with intermediate strength
of background disorder. They are manifested by strong resistance oscillations
induced by high perpendicular magnetic fields B_{\perp}. While the amplitude of
the oscillations is strongly enhanced with increasing B_{\perp}, their position
in density remains unaffected. The observation is accompanied by an unusual
behaviour of the temperature dependence of resistance and activation energies.
We suggest the interplay between a strongly interacting electron phase and the
background disorder as a possible explanation. | 0810.2418v1 |
2009-08-02 | Resistivity noise in crystalline magnetic nanowires and its implications to domain formation and kinetics | We have investigated the time-dependent fluctuations in electrical
resistance, or noise, in high quality crystalline magnetic nanowires within
nanoporous templates. The noise increases exponentially with increasing
temperature and magnetic field, and has been analyzed in terms of domain wall
depinning within the Neel-Brown framework. The frequency-dependence of noise
also indicates a crossover from nondiffusive kinetics to long-range diffusion
at higher temperatures, as well as a strong collective depinning, which need to
be considered when implementing these nanowires in magnetoelectronic devices. | 0908.0136v1 |
2010-07-07 | Selfoscillations of Suspended Carbon Nanotubes with a Deflection Sensitive Resistance under Voltage Bias | We theoretically investigate the electro-mechanics of a Suspended Carbon
Nanotube with a Deflection Sensitive Resistance subjected to a homogeneous
Magnetic Field and a constant Voltage Bias. We show that, (with the exception
of a singular case), for a sufficiently high magnetic field the
time-independent state of charge transport through the nanotube becomes
unstable to selfexcitations of the mechanical vibration accompanied by
oscialltions in the voltage drop and current across the nanotube. | 1007.1139v1 |
2010-07-28 | Inelastic contribution of the resistivity in the hidden order in URu2Si2 | In the hidden order of URu2Si2 the resistivity at very low temperature shows
no T^2 behavior above the transition to superconductivity. However, when
entering the antiferromagnetic phase, the Fermi liquid behavior is recovered.
We discuss the change of the inelastic term when entering the AF phase with
pressure considering the temperature dependence of the Grueneisen parameter at
ambient pressure and the influence of superconductivity by an extrapolation of
high field data. | 1007.4905v1 |
2010-08-23 | Field induced changes across magnetic compensation in Pr(1-x)Gd(x)Al(2) alloys | The magnetic compensation phenomenon has been explored in the
Pr(1-x)Gd(x)Al(2) series. The contributions from Pr and Gd moments compensate
each other at a specific temperature in the ordered state (below (T(c)). At
high fields, the magnetic reorientation (with respect to the external field
direction) of the Pr and Gd moments appears as a minimum in the thermomagnetic
response. We demonstrate several interesting attributes related with the
magnetic reorienation phenomenon, viz., oscillatory behavior of the
magneto-resistance, sign change of the anamalous Hall resistivity, fingerprints
of field induced changes in the specific heat and ac-susceptibility data. | 1008.3782v1 |
2011-01-14 | Hall field-induced resistance oscillations in tilted magnetic fields | We have studied the effect of an in-plane magnetic field on Hall
field-induced resistance oscillations in high mobility two-dimensional electron
systems. We have found that the oscillation frequency depends only on the
perpendicular component of the magnetic field but the oscillation amplitude
decays exponentially with an in-plane component. While these findings cannot be
accounted for by existing theories of nonlinear transport, our analysis
suggests that the decay can be explained by an in-plane magnetic field-induced
modification of the quantum scattering rate. | 1101.2871v2 |
2011-02-24 | Positive speed for high-degree automaton groups | Mother groups are the basic building blocks for polynomial automaton groups.
We show that, in contrast with mother groups of degree 0 or 1, any bounded,
symmetric, generating random walk on the mother groups of degree at least 3 has
positive speed. The proof is based on an analysis of resistance in fractal
mother graphs. We give upper bounds on resistances in these graphs, and show
that infinite versions are tran- sient. | 1102.4979v1 |
2011-03-09 | An efficient multi-use multi-secret sharing scheme based on hash function | In this paper, a renewable, multi-use, multi-secret sharing scheme for
general access structure based on one-way collision resistant hash function is
presented in which each participant has to carry only one share. By applying
collision-resistant one-way hash function, the proposed scheme is secure
against conspiracy attacks even if the pseudo-secret shares are compromised.
Moreover, high complexity operations like modular multiplication,
exponentiation and inversion are avoided to increase its efficiency. Finally,
in the proposed scheme, both the combiner and the participants can verify the
correctness of the information exchanged among themselves. | 1103.1730v1 |
2011-05-28 | Thermo-Resistive Instability in Magnetar Crusts | We investigate a thermo-resistive instability in the outer crusts of
magnetars wherein a perturbation in temperature increases ohmic heating. We
show that magnetars of characteristic age {\tau}_{age} ~ 10^4 yr are unstable
over timescales as short as days if strong current sheets are present in the
outer crust. This instability could play an important role in the thermal and
magnetic field evolution of magnetars, and may be related to bursting activity
in magnetars. | 1105.5712v1 |
2011-10-10 | Non linear transport in drift-diffusion equations under magnetic field | We analyze numerically and analytically the non linear transport properties
of a drift-diffusion equation in presence of a magnetic field and of a disorder
potential. For a wide range of parameters this model exhibits a plateau where
the drift velocity is almost independent on the applied electric field. This
behavior has strong similarities with the zero differential resistance states
observed experimentally in high mobility two dimensional systems. Performed
numerical simulations are in a good global agreement with the developed
analytical theory even if the later leads to overestimated negative
differential resistance values. | 1110.2033v1 |
2012-08-09 | Strange metals at finite 't Hooft coupling | In this paper, we consider the AdS-Schwarzshild black hole in light-cone
coordinates which exhibits non-relativistic z=2 Schrodinger symmetry. Then, we
use the $AdS/CFT$ correspondence to investigate the effect of finite-coupling
corrections to two important properties of the strange metals which are the
Ohmic resistivity and the inverse Hall angle. It is shown that the Ohmic
resistivity and inverse Hall angle are linear and quadratic temperature
dependent in the case of $\mathcal{R}^4$ corrections, respectively. While in
the case of Gauss-Bonnet gravity, we find that the inverse Hall angle is
quadratic temperature dependent and the Ohmic conductivity can never be linear
temperature dependent. | 1208.1855v1 |
2012-11-15 | Microwave-induced resistance oscillations in tilted magnetic fields | We have studied the effect of an in-plane magnetic field on microwave-induced
resistance oscillations in a high mobility two-dimensional electron system. We
have found that the oscillation amplitude decays exponentially with an in-plane
component of the magnetic field $B_\parallel$. While these findings cannot be
accounted for by existing theories, our analysis suggests that the decay can be
explained by a $B_\parallel$-induced correction to the quantum scattering rate,
which is quadratic in $B_\parallel$. | 1211.3753v1 |
2013-07-25 | Negative differential resistance with graphene channels, interfacing distributed quantum dots in Field-Effect Transistors | Field effect transistors with channels made of graphene layer(s) were
explored. The graphene layer(s) contacted a distributed array of well-separated
semiconductor quantum dots (QDs). The dots were embedded in nano-structured
hole-array; each filled hole was occupied by one dot. Differential optical and
electrical conductance was observed. Since Negative Differential Resistance
(NDR) is key to high-speed elements, such construction may open the door for
new electro-photonic devices. | 1307.6790v1 |
2013-09-04 | Exploiting negative differential resistance in monolayer graphene FETs for high voltage gains | Through self-consistent quantum transport simulations, we evaluate the RF
performance of monolayer graphene FETs in the bias region of negative output
differential resistance. We show that, compared to the region of
quasi-saturation, a voltage gain larger than 10 can be obtained, at the cost of
a decrease in the maximum oscillation frequency of about a factor of 1.5--3 and
the need for a careful circuit stabilization. | 1309.1105v2 |
2013-11-01 | Fermi liquid breakdown and evidence for superconductivity in YFe$_2$Ge$_2$ | In the d-electron system YFe$_2$Ge$_2$, an unusually high and temperature
dependent Sommerfeld ratio of the specific heat capacity $C/T \sim
100~\mathrm{mJ/(molK^2)}$ and an anomalous power law temperature dependence of
the electrical resistivity $\rho \simeq \rho_0 + AT^{3/2}$ signal Fermi liquid
breakdown, probably connected to a close-by quantum critical point. Full
resistive transitions, accompanied by DC diamagnetic screening fractions of up
to 80\% suggest that pure samples of YFe$_2$Ge$_2$ superconduct below
$1.8~\mathrm{K}$. | 1311.0247v2 |
2014-04-28 | Resistive Plate Chambers for Imaging Calorimetry - the DHCAL | The DHCAL, the Digital Hadron Calorimeter, is a prototype calorimeter based
on Resistive Plate Chambers (RPCs). The design emphasizes the imaging
capabilities of the detector in an effort to optimize the calorimeter for the
application of Particle Flow Algorithms (PFAs) to the reconstruction of
hadronic jet energies in a colliding beam environment. The readout of the
chambers is segmented into 1 x 1 cm2 pads, each read out with a 1-bit (single
threshold) resolution. The prototype with approximately 500,000 readout
channels underwent extensive testing in both the Fermilab and CERN test beams.
This talk presents preliminary findings from the analysis of data collected at
the test beams. | 1404.7046v2 |
2014-05-07 | Thermal effects and switching kinetics in silver/manganite memristive systems: Probing oxygen vacancies diffusion | We investigate the switching kinetics of oxygen vacancies (Ov) diffusion in
LPCMO-Ag memristive interfaces by performing experiments on the temperature
dependence of the high resistance (HR) state under thermal cycling.
Experimental results are well reproduced by numerical simulations based on
thermally activated Ov diffusion processes and fundamental assumptions relying
on a recent model proposed to explain bipolar resistive switching in manganite-
based cells. The confident values obtained for activation energies and
diffusion coefficient associated to Ov dynamics, constitute a validation test
for both model predictions and Ov diffusion mechanisms in memristive
interfaces. | 1405.1585v1 |
2014-06-26 | Signal Characteristics of a Resistive-Strip Micromegas Detector with an Integrated Two-Dimensional Readout | In recent years, micropattern gaseous detectors, which comprise a
two-dimensional readout structure within one PCB layer, received significant
attention in the development of precision and cost-effective tracking detectors
in medium and high energy physics experiments. In this article, we present for
the first time a systematic performance study of the signal characteristics of
a resistive strip micromegas detector with a two-dimensional readout, based on
test-beam and X-ray measurements. In particular, comparisons of the response of
the two independent readout-layers regarding their signal shapes and signal
reconstruction efficiencies are discussed. | 1406.6871v1 |
2016-06-25 | Linear and quadratic in temperature resistivity from holography | We present a new black hole solution in the asymptotic Lifshitz spacetime
with a hyperscaling violating factor. A novel computational method is
introduced to compute the DC thermoelectric conductivities analytically. We
find that both the linear-T and quadratic-T contributions to the resistivity
can be realized, indicating that a more detailed comparison with experimental
phenomenology can be performed in this scenario. | 1606.07905v3 |
2017-02-18 | Delta-doped Beta- Gallium Oxide Field Effect Transistor | We report silicon delta doping in Gallium Oxide (\b{eta}-Ga2O3) grown by
plasma assisted molecular beam epitaxy using a shutter pulsing technique. We
describe growth procedures that can be used to realize high Si incorporation in
an oxidizing oxygen plasma environment. Delta doping was used to realize thin
(12 nm) low-resistance layers with sheet resistance of 320 Ohm/square (mobility
of 83 cm^2/Vs, integrated sheet charge of 2.4x10^14 cm^-2). A single
delta-doped sheet of carriers was employed as a channel to realize a field
effect transistor with current ID,MAX =292 mA/mm and transconductance gM = 27
mS/mm. | 1702.06584v1 |
2017-11-17 | An HLLC Riemann Solver for Resistive Relativistic Magnetohydrodynamics | We present a new approximate Riemann solver for the augmented system of
equations of resistive relativistic magnetohydrodynamics (RRMHD) that belongs
to the family of Harten-Lax-van Leer contact wave (HLLC) solvers. In HLLC
solvers, the solution is approximated by two constant states flanked by two
shocks separated by a contact wave. The accuracy of the new approximate solver
is calibrated through one- and two-dimensional test problems. | 1711.06691v2 |
2018-02-01 | MHD simulations of resistive viscous accretion disk around millisecond pulsar | We perform MHD simulations of a thin resistive and viscous accretion disk
around a neutron star with the surface dipolar magnetic field of 10$^8$ Gauss.
The system evolution is followed during the interval of 500 millisecond pulsar
rotations. Matter is accreted through a stable accretion column from the disk
onto the star. We also show propagation of the stellar wind through the corona.
Analysis of the mass accretion flux and torques on the star shows that the disk
reaches the quasi-stationary state. | 1802.00261v1 |
2014-08-01 | Nonmetallic Low-Temperature Normal State of K0.70Fe1.46Se1.85Te0.15 | The normal-state in-plane resistivity below the zero-field superconducting
transition temperature $T_c$ and the upper critical field Hc2 were measured by
suppressing superconductivity in pulsed magnetic fields for
K0.70Fe1.46Se1.85Te0.15. The normal-state resistivity $\rho_{ab}$ is found to
increase logarithmically with decrasing temperature as
$\frac{T}{T_c}\rightarrow 0$. Similar to granular metals, our results suggest
that a superconductor - insulator transition below zero-field T$_{c}$ may be
induced in high magnetic fields. This is related to the intrinsic real-space
phase-separated states common to all inhomogeneous superconductors. | 1408.0271v1 |
2020-02-22 | Accelerating longitudinal expansion of resistive relativistic-magneto-hydrodynamics in heavy ion collisions | We study the evolution of the longitudinal expansion of an ideal fluid with
finite electrical conductivity, which is subject to the EM fields. In the
framework of resistive relativistic-magneto-hydrodynamic, we find an exact
analytical solution for the EM fields and for the acceleration of the fluid. | 2002.09752v1 |
2012-01-03 | Sub-Rayleigh lithography using high flux loss-resistant entangled states of light | Quantum lithography achieves phase super-resolution using fragile,
experimentally challenging entangled states of light. We propose a scalable
scheme for creating features narrower than classically achievable, with reduced
use of quantum resources and consequently enhanced resistance to loss. The
scheme is an implementation of interferometric lithography using a mixture of
an SPDC entangled state with intense classical coherent light. We measure
coincidences of up to four photons mimicking multiphoton absorption. The
results show a narrowing of the interference fringes of up to 30% with respect
to the best analogous classical scheme using only 10% of the non-classical
light required for creating NOON states. | 1201.0637v1 |
2017-08-02 | Graphene membrane as a pressure gauge | Straining graphene results in the appearance of a pseudo-magnetic field which
alters its local electronic properties. Applying a pressure difference between
the two sides of the membrane causes it to bend/bulge resulting in a resistance
change. We find that the resistance changes linearly with pressure for bubbles
of small radius while the response becomes non-linear for bubbles that stretch
almost to the edges of the sample. This is explained as due to the strong
interference of propagating electronic modes inside the bubble. Our
calculations show that high gauge factors can be obtained in this way which
makes graphene a good candidate for pressure sensing. | 1708.00678v1 |
2019-12-18 | Large responsivity of graphene radiation detectors with thermoelectric readout | Simple estimations show that the thermoelectric readout in graphene radiation
detectors can be extremely effective even for graphene with modest
charge-carrier mobility ~1000 cm^2/(Vs). The detector responsivity depends
mostly on the residual charge-carrier density and split-gate spacing and can
reach competitive values of ~10^3 - 10^4 V/W at room temperature. The optimum
characteristics depend on a trade-off between the responsivity and the total
device resistance. Finding out the key parameters and their roles allows for
simple detectors and their arrays, with high responsivity and sufficiently low
resistance matching that of the radiation-receiving antenna structures. | 1912.08489v1 |
2012-03-01 | Magnetic and transport properties of iron-platinum arsenide Ca10(Pt4-δAs8)(Fe2-xPtxAs2)5 single crystal | We report superconducting properties of single crystalline
Ca10(Pt4-{\delta}As8)(Fe2-xPtxAs2)5 by X-ray diffraction, magnetization,
resistivity, and magneto-optical imaging measurements. The magnetization
measurements reveal fish-tail hysteresis loop and relatively high critical
current density Jc ~ 0.8\times105 A/cm2 at low temperatures. The exponential
temperature dependence of Jc, which arises from nonlinear effective flux-creep
activation energy, has been observed. Upper critical field determined by
resistive transition shows a relatively large anisotropy. The magneto-optical
images reveal homogenous current flow within the crystal. | 1203.0099v1 |
2012-03-22 | Tungsten silicide films for microwave kinetic inductance detectors | Microwave Kinetic Inductance Detectors (MKIDs) provide highly multiplexed
arrays of detectors that can be configured to operate from the sub-millimeter
to the X-ray regime. We have examined two tungsten silicide alloys (W5Si3 and
WSi2), which are dense alloys that provide a critical temperature tunable with
composition, large kinetic inductance fraction, and high normal-state
resistivity. We have fabricated superconducting resonators and provide
measurement data on critical temperature, surface resistance, quality factor,
noise, and quasiparticles lifetime. Tungsten silicide appears to be promising
for microwave kinetic inductance detectors. | 1203.5064v2 |
2016-09-10 | Angular resolution of stacked resistive plate chambers | We present here detailed derivations of mathematical expressions for the
accuracy in the arrival direction of particles estimated using a set of stacked
resistive plate chambers (RPCs). The expressions are validated against
experimental results using data collected from the prototype detectors (without
magnet) of the upcoming India-based Neutrino Observatory (INO). We also present
a theoretical estimate of angular resolution of such a setup. In principle,
these expressions can be used for any other detector with an architecture
similar to that of RPCs. | 1609.03071v2 |
2016-09-19 | Scaling limits of stochastic processes associated with resistance forms | We establish that if a sequence of spaces equipped with resistance metrics
and measures converge with respect to the Gromov-Hausdorff-vague topology, and
a certain non-explosion condition is satisfied, then the associated stochastic
processes also converge. This result generalises previous work on trees,
fractals, and various models of random graphs. We further conjecture that it
will be applicable to the random walk on the incipient infinite cluster of
critical bond percolation on the high-dimensional integer lattice. | 1609.05666v1 |
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