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6,500 | Quantum transport in semiconductor-superconductor microjunctions | cond-mat.mes-hall | Recent experiments on conduction between a semiconductor and a superconductor
have revealed a variety of new mesoscopic phenomena. Here is a review of the
present status of this rapidly developing field. A scattering theory is
described which leads to a conductance formula analogous to Landauer's formula
in normal-stat... | physics |
6,501 | Mode-Locking in Quantum-Hall-Effect Point Contacts | cond-mat.mes-hall | We study the effect of an ac drive on the current-voltage (I-V)
characteristics of a tunnel junction between two fractional Quantum Hall fluids
at filling $\nu ^{-1}$ an odd integer. Within the chiral Luttinger liquid model
of edge states, the point contact dynamics is described by a driven damped
quantum mechanical pe... | physics |
6,502 | Spectral Fluctuations in Disordered Metals | cond-mat.mes-hall | This is a review of the properties of spectral fluctations in disordered
metals, their relation with Random Matrix Theory and semiclassical picture. We
also review the physics of persistent currents in mesoscopic isolated rings,
the parametric correlations and curvature distributions. | physics |
6,503 | Ultrasmall double junction in terms of orthogonal polynomials | cond-mat.mes-hall | The ``orthodox theory'' of a single electron double junction is dealt with.
It is shown that the stationary solution of the underlying master equation
allows the construction of any time-dependent solution in terms of orthogonal
polynomials. The approach pays off if the stationary solution becomes simple.
Two special c... | physics |
6,504 | Inelastic Electron Lifetime in Disordered Mesoscopic Systems | cond-mat.mes-hall | The inelastic quasiparticle lifetime due to the electron-electron interaction
(out-scattering time in the kinetic equation formalism) is calculated for
finite metallic diffusive systems (quantum dots) in the whole range of
parameters. Both cases of ``continuous'' (the inelastic level broadening much
exceeds the mean le... | physics |
6,505 | Surface acoustic wave attenuation by a two-dimensional electron gas in a strong magnetic field | cond-mat.mes-hall | The propagation of a surface acoustic wave (SAW) on GaAs/AlGaAs
heterostructures is studied in the case where the two-dimensional electron gas
(2DEG) is subject to a strong magnetic field and a smooth random potential with
correlation length Lambda and amplitude Delta. The electron wave functions are
described in a qua... | physics |
6,506 | Correlated ground states with (spontaneously) broken time-reversal symmetry | cond-mat.mes-hall | We propose a self-consistent scheme for the determination of the ground-state
(GS) properties of interacting electrons in a magnetic field, and of systems
whose GS's time-reversal-symmetry (TRS) is spontaneously broken. It is based on
a newly-developed many-body perturbation theory that is valid, irrespective of
the st... | physics |
6,507 | Statistics of skyrmions and the 5/2 puzzle | cond-mat.mes-hall | 1) For the hard core interaction there is some freedom left in the choice of
the exact multiskyrmionic wave function's topology. The statistics of textured
quasiholes, analyzed by calculation of the Berry phase, depends on this choice
of topology.
2) We find a class of textured two-hole eigenstates of the Coulomb
int... | physics |
6,508 | Transport through a single-band wire connected to measuring leads | cond-mat.mes-hall | Transport through a one-dimensional wire of interacting electrons connected
to semi infinite leads is investigated using a bosonization approach. The
dynamic nonlocal conductivity is rigorously expressed in terms of the
transmission. For abrupt variations of the interaction parameters at the
junctions, an incident elec... | physics |
6,509 | Spin-Excitation-Instability-Induced Quantum Phase Transitions in Double-Layer Quantum Hall Systems | cond-mat.mes-hall | We study intersubband spin density collective modes in double-layer quantum
Hall systems at $\nu=2$ within the time-dependent Hartree-Fock approximation.
We find that these intersubband spin density excitations may soften under
experimentally accessible conditions, signaling a phase transition to a new
quantum Hall sta... | physics |
6,510 | Addition Spectrum Oscillations of Fractional Quantum Hall Dots | cond-mat.mes-hall | Quantum dots in the fractional quantum Hall regime are studied using a
Hartree formulation of composite fermion theory. Under appropriate conditions
the chemical potential of the dots will oscillate periodically with B due to
the transfer of composite fermions between quasi-Landau bands. This effect is
analogous to the... | physics |
6,511 | Measurement of the conductance distribution function at a quantum Hall transition | cond-mat.mes-hall | We study experimentally the reproducible conductance fluctuations between the
quantum Hall plateaus in the conductance of two-terminal submicron silicon
MOSFETs. For the dramatic fluctuations at the insulator-to-first-plateau
transition we find a conductance distribution that is approximately uniform
between zero and $... | physics |
6,512 | Theory of Photoluminescence of the $ν=1$ Quantum Hall State: Excitons, Spin-Waves and Spin-Textures | cond-mat.mes-hall | We study the theory of intrinsic photoluminescence of two-dimensional
electron systems in the vicinity of the $\nu=1$ quantum Hall state. We focus
predominantly on the recombination of a band of initial ``excitonic states''
that are the low-lying energy states of our model at $\nu=1$. It is shown that
the recombination... | physics |
6,513 | Coherent photon assisted cotunneling in a Coulomb blockade device | cond-mat.mes-hall | We study cotunneling in a double junction Coulomb blockade device under the
influence of time dependent potentials. It is shown that the ac-bias leads to
photon assisted cotunneling which in some cases may dominate the transport. We
derive a general non-perturbative expression for the tunneling current in the
presence ... | physics |
6,514 | Spectral correlations in disordered mesoscopic metals and their relevance for persistent currents | cond-mat.mes-hall | We use the Lanczos method to calculate the variance of the number of energy
levels in an energy window of width E below the Fermi energy for
non-interacting disordered electrons on a thin three-dimensional ring threaded
by an Aharonov-Bohm flux . We find that for small E the flux-dependent part of
the variance is well ... | physics |
6,515 | Symmetry-breaking skyrmion states in fractional quantum Hall systems | cond-mat.mes-hall | We calculate in an analyical fashion the energies and net spins of skyrmions
in fractional quantum Hall systems, based on the suggestion that skyrmion
states are spontaneously $L_Z$ and $S_Z$ symmetry-breaking states. The
quasihole-skyrmion state with a charge $-e/3$ around $\nu$ = 1/3, where the
ground state is known ... | physics |
6,516 | Statistical properties of the low-temperature conductance peak-heights for Corbino discs in the quantum Hall regime | cond-mat.mes-hall | A recent theory has provided a possible explanation for the ``non-universal
scaling'' of the low-temperature conductance (and conductivity) peak-heights of
two-dimensional electron systems in the integer and fractional quantum Hall
regimes. This explanation is based on the hypothesis that samples which show
this behavi... | physics |
6,517 | Critical Conductance and Its Fluctuations at Integer Hall Plateau Transitions | cond-mat.mes-hall | Under periodic boundary condition in the transverse direction, we calculate
the averaged zero-temperature two-terminal conductance ($<G>$) and its
statistical fluctuations ($<(\dg)^{2n}>$ for $n\le 4$) at the critical point of
integer quantum Hall plateau transitions. We find {\it universal} values for
$<G>=(0.58\pm0.0... | physics |
6,518 | Theory of anyon excitons: Relation to excitons of nu=1/3 and nu=2/3 incompressible liquids | cond-mat.mes-hall | Elementary excitations of incompressible quantum liquids (IQL's) are anyons,
i.e., quasiparticles carrying fractional charges and obeying fractional
statistics. To find out how the properties of these quasiparticles manifest
themselves in the optical spectra, we have developed the anyon exciton model
(AEM) and compared... | physics |
6,519 | Conductance fluctuations at the integer quantum Hall plateau transition | cond-mat.mes-hall | We study numerically conductance fluctuations near the integer quantum Hall
effect plateau transition. The system is presumed to be in a mesoscopic regime,
with phase coherence length comparable to the system size. We focus on a
two-terminal conductance G for square samples, considering both periodic and
open boundary ... | physics |
6,520 | Coulomb drag in mesoscopic rings | cond-mat.mes-hall | We develop a Luttinger liquid theory of the Coulomb drag of persistent
currents flowing in concentric mesoscopic rings, by incorporating non-linear
corrections to the electron dispersion relation. We demonstrate that at low
temperatures, interactions between electrons in different rings generate an
additional phase and... | physics |
6,521 | Fluctuations of Conductance Peak Spacings in the Coulomb Blockade Regime: Role of Electron-Electron Interaction | cond-mat.mes-hall | We study influence of electron-electron interaction on statistics of Coulomb
blockade peak spacings in disordered quantum dots. It is shown that the
interaction combined with fluctuations of eigenfunctions of the Fermi sea,
enhances the peak spacing fluctuations, in accordance with recent experiments.
In addition, acco... | physics |
6,522 | The Quantum Hall Effect of Interacting Electrons in a Periodic Potential | cond-mat.mes-hall | We consider the influence of an external periodic potential on the fractional
quantum Hall effect of two-dimensional interacting electron systems. For many
electrons on a torus, we find that the splitting of incompressible ground state
degeneracies by a weak external potential diminishes as $\exp ( - L/ \xi)$ at
large ... | physics |
6,523 | Admittance and Nonlinear Transport in Quantum Wires, Point Contacts, and Resonant Tunneling Barriers | cond-mat.mes-hall | We present a discussion of the admittance (ac-conductance) and nonlinear
I-V-characteristic for a number of mesoscopic conductors. Our approach is based
on a generalization of the scattering approach which now includes the effects
of the (long-range) Coulomb interaction. We discuss the admittance of a wire
with an impu... | physics |
6,524 | Transport in a one-dimensional Luttinger liquid | cond-mat.mes-hall | In this paper we review recent theoretical results for transport in a
one-dimensional (1d) Luttinger liquid. For simplicity, we ignore electron spin,
and focus exclusively on the case of a single-mode. Moreover, we consider only
the effects of a single (or perhaps several) spatially localized impurities.
Even with thes... | physics |
6,525 | Hopf term and the effective Lagrangian for the Skyrmions in a two-dimensional electron gas at small g-factor | cond-mat.mes-hall | We study interacting electrons in two dimensions moving in the lowest Landau
level under the condition that the Zeeman energy is much smaller than the
Coulomb energy and the filling factor is one. In this case, Skyrmion
quasiparticles play an important role. Here, we present a simple and
transparent derivation of the c... | physics |
6,526 | Exact density of states of a two-dimensional electron gas in a strong magnetic field and a long-range correlated random potential | cond-mat.mes-hall | We derive an exact result for the averaged Feynman propagator and the
corresponding density of states of an electron in two dimensions in a
perpendicular homogeneous magnetic field and a Gaussian random potential with
long-range spatial correlations described by a quadratic correlation function. | physics |
6,527 | nu=1/2 quantum Hall effect in the Aharonov-Casher geometry in a mesoscopic ring | cond-mat.mes-hall | We study the effect of an electric charge in the middle of a ring of
electrons in a magnetic field such as $\nu = 1/2$. In the absence of the
central charge, a residual current should appear due to an Aharanov-Bohm
effect. As the charge varies, periodic currents should appear in the ring. We
evaluate the amplitude of t... | physics |
6,528 | Classical and Quantum Chaos in a quantum dot in time-periodic magnetic fields | cond-mat.mes-hall | We investigate the classical and quantum dynamics of an electron confined to
a circular quantum dot in the presence of homogeneous $B_{dc}+B_{ac}$ magnetic
fields. The classical motion shows a transition to chaotic behavior depending
on the ratio $\epsilon=B_{ac}/B_{dc}$ of field magnitudes and the cyclotron
frequency ... | physics |
6,529 | Electron dynamics in intentionally disordered semiconductor superlattices | cond-mat.mes-hall | We study the dynamical behavior of disordered quantum-well-based
semiconductor superlattices where the disorder is intentional and short-range
correlated. We show that, whereas the transmission time of a particle grows
exponentially with the number of wells in an usual disordered superlattice for
any value of the incid... | physics |
6,530 | Magneto-polarisability of mesoscopic rings | cond-mat.mes-hall | We calculate the average polarisability of two dimensional mesoscopic rings
in the presence of an Aharonov-Bohm flux. The screening is taken into account
self-consistently within a mean-field approximation. We investigate the effects
of statistical ensemble, finite frequency and disorder. We emphasize
geometrical effec... | physics |
6,531 | Duality Near Quantum Hall Transitions | cond-mat.mes-hall | A recent experiment by Shahar et al, on the phase transitions between quantum
Hall states and the insulator, found that the current-voltage characteristics
in the two phases are related by symmetry. It was suggested in this work that
this is evidence for charge-flux duality near quantum Hall transitions. Here we
provid... | physics |
6,532 | Electron Capture into Quantum Wells via Scattering by Electrons, Holes, and Optical Phonons | cond-mat.mes-hall | Electron capture times due to the electron-electron (e-e), electron-hole
(e-h) and electron-polar optical phonon (e-pop) interactions are calculated in
the GaAs quantum well (QW) with electron and hole densities 10^11 cm^-2. The
calculated capture times oscillate as a function of the QW width with the same
period but w... | physics |
6,533 | Landau level mixing and spin degeneracy in the quantum Hall effect | cond-mat.mes-hall | We study dynamics of electrons in a magnetic field using a network model with
two channels per link with random mixing in a random intrachannel potential;
the channels represent either two Landau levels or two spin states. We consider
channel mixing as function of the energy separation of the two extended states
and sh... | physics |
6,534 | Impact of interface roughness on perpendicular transport and domain formation in superlattices | cond-mat.mes-hall | A microscopic calculation of the perpendicular current in doped multiple
quantum wells is presented. Interface roughness is shown to affect the resonant
transitions as well as to cause a nonresonant background current. The
theoretical characteristics exhibit several branches due to the formation of
electric field domai... | physics |
6,535 | Microscopic modelling of perpendicular electronic transport in doped multiple quantum wells | cond-mat.mes-hall | We present a microscopic calculation of transport in strongly doped
superlattices where domain formation is likely to occur. Our theoretical method
is based on a current formula involving the spectral functions of the system,
and thus allows, in principle, a systematic investigation of various
interaction mechanisms. T... | physics |
6,536 | Multifractality beyond the Parabolic Approximation: Deviations from the Log-normal Distribution at Criticality in Quantum Hall Systems | cond-mat.mes-hall | Based on differences of generalized R\'enyi entropies nontrivial constraints
on the shape of the distribution function of broadly distributed observables
are derived introducing a new parameter in order to quantify the deviation from
lognormality. As a test example the properties of the two--measure random
Cantor set a... | physics |
6,537 | Dynamical phenomena in Fibonacci Semiconductor Superlattices | cond-mat.mes-hall | We present a detailed study of the dynamics of electronic wavepackets in
Fibonacci semiconductor superlattices, both in flat band conditions and subject
to homogeneous electric fields perpendicular to the layers. Coherent
propagation of electrons is described by means of a scalar Hamiltonian using
the effective-mass ap... | physics |
6,538 | Charge-Relaxation and Dwell Time in the fluctuating Admittance of a Chaotic Cavity | cond-mat.mes-hall | We consider the admittance of a chaotic quantum dot, capacitively coupled to
a gate and connected to two electron reservoirs by multichannel ballistic point
contacts. For a dot in the regime of weak-localization and universal
conductance fluctuations, we calculate the average and variance of the
admittance using random... | physics |
6,539 | Exact shape of the lowest Landau level in a spin-1/2 system with uncorrelated disorders | cond-mat.mes-hall | Using the path-integral approach developed by Br\'ezin et al. [
Nucl.Phys.B235, 24 (1984) ], we obtain an analytical expression for the density
of states of a spin-1/2 disordered two-dimensional electron gas in a strong,
perpendicular magnetic field. The density of states of this system illustrates
the interplay betwee... | physics |
6,540 | Nonlinearity in NS transport: scattering matrix approach | cond-mat.mes-hall | A general formula for the current through a disordered
normal--superconducting junction is derived, which is valid at finite
temperature and includes the full voltage dependence. The result depends on a
multichannel scattering matrix, which describes elastic scattering in the
normal region, and accounts for the Andreev... | physics |
6,541 | Hofstadter Rules and Generalized Dimensions of the Spectrum of Harper's Equation | cond-mat.mes-hall | We consider the Harper model which describes two dimensional Bloch electrons
in a magnetic field. For irrational flux through the unit-cell the
corresponding energy spectrum is known to be a Cantor set with multifractal
properties. In order to relate the maximal and minimal fractal dimension of the
spectrum of Harper's... | physics |
6,542 | Persistent currents in continuous one-dimensional disordered rings within the Hartree--Fock approximation | cond-mat.mes-hall | We present numerical results for the zero temperature persistent currents
carried by interacting spinless electrons in disordered one dimensional
continuous rings. The disorder potential is described by a collection of
delta-functions at random locations and strengths. The calculations are
performed by a self-consisten... | physics |
6,543 | Suppresion of Bloch oscillations by weak disorder in semiconductor superlattices | cond-mat.mes-hall | We investigate the dephasing dynamics of Bloch oscillations in semiconductor
superlattices by means of a very simple model including disorder and applied
electric fields. A thorough numerical study of our model allows us to claim
that small, unintentional well width fluctuations can be responsible for fast
dephasing of... | physics |
6,544 | Persistent Current in an Artificial Quantum Dot Molecule | cond-mat.mes-hall | Using an exact diagonalization technique within a generalized Mott-Hubbard
Hamiltonian, we predict the existence of a ground state persistent current in
coherent two-dimensional semiconductor quantum dot arrays pierced by an
external magnetic flux. The calculated persistent current, which arises from
the nontrivial dep... | physics |
6,545 | Interaction effects in multi-subband quantum wires | cond-mat.mes-hall | We investigate the effect of electron-electron interactions on the transport
properties of disordered quasi one-dimensional quantum wires with two or more
subbands occupied. We apply two alternative methods to solve the logarithmic
divergent problem, namely the parquet graph theory and a renormalization group
calculati... | physics |
6,546 | Compressibility, capacitance and ground state energy fluctuations in a weakly interacting quantum dot | cond-mat.mes-hall | We study the effect of electron-electron (e-e) interactions on
compressibility, capacitance and inverse compressibility of electrons in a
quantum dot or a small metallic grain. The calculation is performed in the
random-phase approximation. As expected, the ensemble-averaged compressibility
and capacitance decreases as... | physics |
6,547 | Effect of Umklapp Scattering on the Conductance in Quantum Wires | cond-mat.mes-hall | We investigate the system-size dependence as well as the temperature
dependence of the conductance in 1D electron systems, paying particular
attention to the effect of Umklapp scattering. By taking into account the
renormalization of the external potential due to electron-electron interaction,
the correction to the con... | physics |
6,548 | Microscopic analytical theory of a correlated, two-dimensional N-electron gas in a magnetic field | cond-mat.mes-hall | We present a microscopic, analytical theory describing a confined N-electron
gas in two dimensions subject to an external magnetic field. The number of
electrons N and strength of the electron-electron interaction can be
arbitrarily large, and all Landau levels are included implicitly. A possible
connection with the In... | physics |
6,549 | Comment on ``New Class of Resonances at the Edge of the Two-Dimensional Electron Gas:'' self-consistent electronic structure | cond-mat.mes-hall | Self-consistent electronic structure calculations, for devices recently
fabricated and studied by Zhitenev et al. for capacitance spectroscopy in the
quantum Hall regime, demonstrate that reproducible resonances in the coupling
between adiabatically free edge states and isolated ``puddles'' of electrons of
higher filli... | physics |
6,550 | Landau level bosonization of a 2D electron gas | cond-mat.mes-hall | In this work we introduce a bosonization scheme for the low energy
excitations of a 2D interacting electron gas in the presence of an uniform
magnetic field under conditions where a large integral number of Landau levels
are filled. We give an explicit construction for the electron operator in terms
of the bosons. We s... | physics |
6,551 | A different view of the quantum Hall plateau-to-plateau transitions | cond-mat.mes-hall | We demonstrate experimentally that the transitions between adjacent integer
quantum Hall (QH) states are equivalent to a QH-to-insulator transition
occurring in the top Landau level, in the presence of an inert background of
the other completely filled Landau levels, each contributing a single unit of
quantum conductan... | physics |
6,552 | Chiral Metal as a Heisenberg Ferromagnet | cond-mat.mes-hall | The two dimensional surface of an integer quantum hall multilayer is mapped
onto a Heisenberg spin-chain with ferromagnetic coupling. Using this mapping it
is shown non-perturbatively that the surface states constitute a very
anisotropic metal in the infinite size limit. For multilayers of finite size,
two diffusive me... | physics |
6,553 | Topological Excitations in Double-Layer Quantum Hall systems | cond-mat.mes-hall | Double-layer quantum Hall systems with spontaneous broken symmetry can
exhibit a novel manybody quantum Hall effect due to the strong interlayer
coherence. When the layer separation becomes close to the critical value,
quantum fluctuations can destroy the interlayer coherence and the quantum Hall
effect will disappear.... | physics |
6,554 | Current Carrying States in a Random Magnetic Field | cond-mat.mes-hall | We report results of a numerical study of noninteracting electrons moving in
two dimensions, in the presence of a random potential and a random magnetic
field for a sequence of finite sizes, using topological properties of the wave
functions to identify extended states. Our results are consistent with the
existence of ... | physics |
6,555 | Coulomb blockade threshold in inhomogeneous one-dimensional arrays of tunnel junctions | cond-mat.mes-hall | A general expression is given for the change in free energy when a charge
tunnels through a junction in a one-dimensional array of N metallic islands
with arbitrary capacitances and arbitrary background charges. This is used to
obtain expressions for the (average) threshold voltage of the Coulomb blockade
for a few cha... | physics |
6,556 | Level Curvatures and Conductances: A Numerical Study of the Thouless Relation | cond-mat.mes-hall | The Thouless conjecture states that the average conductance of a disordered
metallic sample in the diffusive regime can be related to the sensitivity of
the sample's spectrum to a change in the boundary conditions. Here we present
results of a direct numerical study of the conjecture for the Anderson model.
They were o... | physics |
6,557 | Current noise, electron-electron interactions, and quantum interference | cond-mat.mes-hall | It is shown that electron-electron interactions lead to a novel
quantum-interference contribution to non-equilibrium current noise in
mesoscopic conductors. The corresponding noise spectrum is obtained in detail
for diffusive systems. It is found to be quadratic in the applied voltage and
to exhibit a power-law frequen... | physics |
6,558 | Skyrmions in Quantum Hall Systems with Realistic Force-Laws | cond-mat.mes-hall | We study the charged excitations of quantum Hall systems at integer filling
fractions $\nu=2n+1$, for a force-law that takes account of the finite width of
the electron gas. For typical values of this width, in the limit of vanishing
Zeeman energy we find that the low-energy excitations are ``skyrmions'' not
only at $\... | physics |
6,559 | Spectral Function Analysis of Fermi Liquids and of Composite Fermions in a Finite Magnetic Field: Renormalised Gaps | cond-mat.mes-hall | We consider the self-energy and quasiparticle spectrum, for both electrons
interacting with phonons, and composite fermions interacting with gauge
fluctuations. In both cases we incorporate the singular structure arising from
Landau level quantization in a finite field. This is then used to determine the
renormalised g... | physics |
6,560 | Electron Refrigeration in the Tunneling Approach | cond-mat.mes-hall | The qualities of electron refrigeration by means of tunnel junctions between
superconducting and normal--metal electrodes are studied theoretically. A
suitable approximation of the basic expression for the heat current across
those tunnel junctions allows the investigation of several features of the
device such as its ... | physics |
6,561 | A new uncertainty Relation (revised version) | cond-mat.mes-hall | We formulate according to the quantum mechanical uncertainty relation a new
quantum electrodynamical uncertainty relation $\Delta \breve{A} . \Delta l \sim
\hbar/e$ where $\breve{A}$ and $\Delta l \geq l_B$ are the electromagnetic pure
gauge potential, the position uncertainty and the magnetic length,
respectively. The... | physics |
6,562 | Scaling Behavior and Universality near the Quantum Hall Transition | cond-mat.mes-hall | A two-dimensional lattice system of non-interacting electrons in a
homogeneous magnetic field with half a flux quantum per plaquette and a random
potential is considered. For the large scale behavior a supersymmetric theory
with collective fields is constructed and studied within saddle point
approximation and fluctuat... | physics |
6,563 | Electron-Hole Correlation in Fractional Quantum Hall Systems | cond-mat.mes-hall | The 2D system of electron confined to the lowest Landau level is described
using a representation of the density matrix depending both on electron and
hole coordinates. Condensation of the electron system into a fractional quantum
Hall state is associated to clustering of particle and hole coordinates. The
correlation ... | physics |
6,564 | Quantum Fluctuations in the Equilibrium State of a Thin Superconducting Loop | cond-mat.mes-hall | We study the oscillatory flux dependence of the supercurrent in a thin
superconducting loop, closed by a Josephson junction. Quantum fluctuations of
the order parameter in the loop affect the shape and renormalize the amplitude
of the supercurrent oscillations. In a short loop, the amplitude of the
sinusoidal flux depe... | physics |
6,565 | Diagrammatic analysis of the two-state quantum Hall system with chiral invariance | cond-mat.mes-hall | The quantum Hall system in the lowest Landau level with Zeeman term is
studied by a two-state model, which has a chiral invariance. Using a
diagrammatic analysis, we examine this two-state model with random impurity
scattering, and find the exact value of the conductivity at the Zeeman energy
$E = \Delta$. We further s... | physics |
6,566 | Plasmons, Magnetoplasmons and the ν= 1/2 Quantum Hall Effect | cond-mat.mes-hall | We address the problem of separating the short-distance, high-energy physics
of cyclotron motion from the long- distance, low-energy physics within the
Lowest Landau Level in field theoretic treatments of the Fractional Quantum
Hall Effect. We illustrate our method for the case $\nu =1/2$. By a sequence of
field transf... | physics |
6,567 | Nonuniversal Critical Conductance Fluctuations of Chiral Surface States in the Bulk Integral Quantum Hall Effect -- An Exact Calculation | cond-mat.mes-hall | The chiral surface electrons in the bulk quantum Hall effect probably form
the first extended system in which conductance fluctuations can be calculated
non-perturbatively in the presence of disorder. By use of the Kubo formula with
appropriate boundary conditions, we calculate exactly the variance of
conductance with ... | physics |
6,568 | Quasi-particle behavior of composite fermions in the half-filled Landau level | cond-mat.mes-hall | We calculate the effect of infrared fluctuations of the Chern-Simons gauge
field on the single-particle Green's function of composite fermions in the
half-filled Landau level via higher-dimensional bosonization on a curved Fermi
surface. We find that composite fermions remain well-defined quasi-particles,
with an effec... | physics |
6,569 | Shot noise in mesoscopic systems | cond-mat.mes-hall | This is a review of shot noise, the time-dependent fluctuations in the
electrical current due to the discreteness of the electron charge, in small
conductors. The shot-noise power can be smaller than that of a Poisson process
as a result of correlations in the electron transmission imposed by the Pauli
principle. This ... | physics |
6,570 | N electrons in a quantum dot: Two-point Pade approximants | cond-mat.mes-hall | We present analytic estimates for the energy levels of N electrons (N = 2 -
5) in a two-dimensional parabolic quantum dot. A magnetic field is applied
perpendicularly to the confinement plane. The relevant scaled energy is shown
to be a smooth function of the parameter \beta=(effective Rydberg/effective dot
energy)^{1/... | physics |
6,571 | Orbital Magnetism in Two-dimensional Integrable Systems | cond-mat.mes-hall | We study orbital magnetism of a degenerate electron gas in a number of
two-dimensional integrable systems, within linear response theory. There are
three relevant energy scales: typical level spacing, the energy related to the
inverse time of flight across the system, and the Fermi energy.
Correspondingly, there are th... | physics |
6,572 | Reflection symmetry at a B=0 metal-insulator transition in two dimensions | cond-mat.mes-hall | We report a remarkable symmetry between the resistivity and conductivity on
opposite sides of the B=0 metal-insulator transition in a two-dimensional
electron gas in high-mobility silicon MOSFET's. This symmetry implies that the
transport mechanisms on the two sides are related. | physics |
6,573 | Quantum Transport in Two-Channel Fractional Quantum Hall Edges | cond-mat.mes-hall | We study the effect of backward scatterings in the tunneling at a point
contact between the edges of a second level hierarchical fractional quantum
Hall states. A universal scaling dimension of the tunneling conductance is
obtained only when both of the edge channels propagate in the same direction.
It is shown that th... | physics |
6,574 | Skyrmion Liquid Phase of the Quantum Ferromagnet in Two Dimensions | cond-mat.mes-hall | The two-dimensional quantum ferromagnet filled with a liquid of skyrmions is
studied theoretically in the context of the quantum Hall effect near electronic
filling factor $\nu = 1$. A cross-over between the classical ferromagnetic
phase at $\nu =1$ and a classical paramagnetic phase at $\nu \neq 1$ is
obtained, which ... | physics |
6,575 | Photoluminescence signature of skyrmions at ν= 1 | cond-mat.mes-hall | The photoluminescence spectrum of quantized Hall states near filling factor
\nu = 1 is investigated theoretically. For \nu >= 1 the spectrum consists of a
right-circularly polarized (RCP) line and a left-circularly polarized (LCP)
line, whose mean energy: (1) does not depend on the electron g factor for
spin-1/2 quasie... | physics |
6,576 | Anomalous temperature dependence of the supercurrent through a chaotic Josephson junction | cond-mat.mes-hall | We calculate the supercurrent through a Josephson junction consisting of a
phase-coherent metal particle (quantum dot), weakly coupled to two
superconductors. The classical motion in the quantum dot is assumed to be
chaotic on time scales greater than the ergodic time $\tau_{erg}$, which itself
is much smaller than the... | physics |
6,577 | Corrections to the universal behavior of the Coulomb-blockade peak splitting for quantum dots separated by a finite barrier | cond-mat.mes-hall | Building upon earlier work on the relation between the dimensionless interdot
channel conductance g and the fractional Coulomb-blockade peak splitting f for
two electrostatically equivalent dots, we calculate the leading correction that
results from an interdot tunneling barrier that is not a delta-function but,
rather... | physics |
6,578 | An exact expression of the collective excitation energy gap of fractional quantum Hall effect | cond-mat.mes-hall | We have exactly solved the eigenequation of a two-dimensional Dirac fermion
moving on the surface of a sphere under the influence of a radial magnetic
field B, and obtained an exact expression of the collective excitation energy
gap for the filling factors $\nu=p/(2mp\pm 1)$, m and p are non-zero integers,
which is ver... | physics |
6,579 | Electric field effects in Fibonacci superlaticces | cond-mat.mes-hall | We present a throughout study of transmission and localization properties of
Fibonacci superlattices, both in flat band conditions and subject to
homogeneous electric fields perpendicular to the layers. We use the transfer
matrix formalism to determine the transmission coefficient and the degree of
localization of the ... | physics |
6,580 | Nonequilibrium transport and population inversion in double quantum dot systems | cond-mat.mes-hall | We present a microscopic theory for both equilibrium and nonequilibrium
transport properties of coupled double quantum dots (DQD). A general formula
for current tunneling through the DQD is derived by the nonequilibrium Green's
function method. Using a Hartree-Fock approach, effects of multi-level coupling
and nonequil... | physics |
6,581 | Nonlinear Transport through Coupled Double Quantum Dot Systems | cond-mat.mes-hall | We investigate sequential tunneling transport through a semiconductor double
quantum dot structure by combining a simple microscopic quantum confinement
model with a Mott-Hubbard type correlation model. We calculate
nonperturbatively the evolution of the Coulomb blockade oscillations as a
function of the interdot barri... | physics |
6,582 | Quantum interference from sums over closed paths for electrons on a three-dimensional lattice in a magnetic field: total energy, magnetic moment, and orbital susceptibility | cond-mat.mes-hall | We study quantum interference effects due to electron motion on a
three-dimensional cubic lattice in a continuously-tunable magnetic field of
arbitrary orientation and magnitude. These effects arise from the interference
between magnetic phase factors associated with different electron closed paths.
The sums of these p... | physics |
6,583 | Analytical results on quantum interference and magnetoconductance for strongly localized electrons in a magnetic field: Exact summation of forward-scattering paths | cond-mat.mes-hall | We study quantum interference effects on the transition strength for strongly
localized electrons hopping on 2D square and 3D cubic lattices in the presence
of a magnetic field B. These effects arise from the interference between phase
factors associated with different electron paths connecting two distinct sites.
For ... | physics |
6,584 | Thermal activation of exclusonic quasiparticles in the fractional quantum Hall effect | cond-mat.mes-hall | Quasiparticles of the fractional quantum Hall systems obey fractional
(including mutual) exclusion statistics. In this note we study the effects of
exclusion statistics on thermal activation of quasiparticle pairs in the
approximation of generalized ideal gas. The distribution function for thermally
activated quasipart... | physics |
6,585 | Interaction dependence of composite fermion effective masses | cond-mat.mes-hall | We estimate the composite fermion effective mass for a general two particle
potential r^{-\alpha} using exact diagonalization for polarized electrons in
the lowest Landau level on a sphere. Our data for the ground state energy at
filling fraction \nu=1/2 as well as estimates of the excitation gap at \nu=1/3,
2/5 and 3/... | physics |
6,586 | Spectral Compressibility at the Metal-Insulator Transition of the Quantum Hall Effect | cond-mat.mes-hall | The spectral properties of a disordered electronic system at the
metal-insulator transition point are investigated numerically. A recently
derived relation between the anomalous diffusion exponent $\eta$ and the
spectral compressibility $\chi$ at the mobility edge, $\chi=\eta/2d$, is
confirmed for the integer quantum H... | physics |
6,587 | Mesoscopic Behavior Near a Two-Dimensional Metal-Insulator Transition | cond-mat.mes-hall | We study conductance fluctuations in a two-dimensional electron gas as a
function of chemical potential (or gate voltage) from the strongly insulating
to the metallic regime. Power spectra of the fluctuations decay with two
distinct exponents (1/v_l and 1/v_h). For conductivity $\sigma\sim 0.1
e^{2}/h$, we find a third... | physics |
6,588 | Coulomb drag in double layer electron systems at even denominator filling factors | cond-mat.mes-hall | An interacting double layer system, with uniform positive background, is
studied at finite temperature in the presense of a strong magnetic field
corresponding to half filling in each layer. By mapping this system to
composite fermions in zero field, we investigate the momentum transfer rate
between the layers. As a re... | physics |
6,589 | Impurity bands and sequential resonant tunneling in the presence of terahertz fields | cond-mat.mes-hall | A theoretical and experimental study of transport in a low doped multiple
quantum well structure shows that impurity bands are essential in understanding
the electronic transport both with and without terahertz irradiation. A full
self-contained model, which involves only the nominal parameters of the sample,
agrees qu... | physics |
6,590 | Electron conduction within Landau level tails of medium-mobility GaAs / AlGaAs heterostructures | cond-mat.mes-hall | The temperature dependence of both components of the resistivity tensor
$\varrho_{xx}(T)$ and $\varrho_{xy}(T)$ has been studied at T $\geq$ 4.2 K
within IQHE plateaux around filling factors \nu=2 and \nu=4 of medium-
-mobility GaAs/AlGaAs heterostructures. In the middle of the mobility gap
standard activated conductiv... | physics |
6,591 | Boundary Conditions for Bulk and Edge States in Quantum Hall Systems | cond-mat.mes-hall | For two dimensional Schroedinger Hamiltonians we formulate boundary
conditions that split the Hilbert space according to the chirality of the
eigenstates on the boundary. With magnetic fields, and in particular, for
Quantum Hall Systems, this splitting corresponds to edge and bulk states.
Applications to the integer an... | physics |
6,592 | Resistivity due to a Domain Wall in Ferromagnetic Metal | cond-mat.mes-hall | The resistivity due to a domain wall in ferromagnetic metallic wire is
calculated based on the linear response theory. The interaction between
conduction electrons and the wall is expressed in terms of a classical gauge
field which is introduced by the local gauge transformation in the electron
spin space. It is shown ... | physics |
6,593 | Fine structure in the off-resonance conductance of small Coulomb blockade systems | cond-mat.mes-hall | We show how a fine, multiple-peak structure can arise in the off-resonance,
zero-bias conductance of Coulomb blockade systems. In order to understand how
this effect comes about one must abandon the orthodox, mean-field understanding
of the Coulomb blockade phenomenon and consider quantum fluctuations in the
occupation... | physics |
6,594 | Generalized thermodynamic potentials for mesoscopic conductors in the presence of transport | cond-mat.mes-hall | It is shown that the nonequilibrium steady-state of a phase-coherent
conductor can be described by a generalized thermodynamic potential based on
the concept of partial densities of states. This is possible due to the fact
that dissipation takes place only in the contacts for the emitted carriers.
Long-range Coulomb in... | physics |
6,595 | Transition from ν=8/5 to ν=5/3 in the low Zeeman energy limit | cond-mat.mes-hall | Skyrmions in the FQHE at filling fractions above \nu=1/3 are studied within
the anyon model and by exact diagonalization. Relations to the composite
fermion theory are pointed out. We find that unpolarized quasiparticles above
\nu=1/3 are stable below B\approx 0.02T. At low Zeeman energy the polarization
in the range \... | physics |
6,596 | Screening of persistent currents in mesoscopic metal rings | cond-mat.mes-hall | The effect of the Coulomb-interaction on persistent currents in disordered
mesoscopic metal rings threaded by a magnetic flux $\phi$ is studied
numerically. We use the simplest form of ``self-consistent'' Hartree theory,
where the spatial variations of the self-consistent Hartree potential are
ignored. In this approxim... | physics |
6,597 | Quantum Coulomb Blockade in Chaotic Systems | cond-mat.mes-hall | We study the Coulomb blockade in a chaotic cavity connected to a lead by a
perfectly transmitting quantum channel. In contrast to the previous theories,
we show that the quantum fluctuations of charge, resulting from the perfect
transmission, do not destroy the Coulomb blockade completely. The oscillatory
dependence of... | physics |
6,598 | Quantum Intermittency in Almost-Periodic Lattice Systems Derived from their Spectral Properties | cond-mat.mes-hall | Hamiltonian tridiagonal matrices characterized by multi-fractal spectral
measures in the family of Iterated Function Systems can be constructed by a
recursive technique here described. We prove that these Hamiltonians are
almost-periodic. They are suited to describe quantum lattice systems with
nearest neighbours coupl... | physics |
6,599 | Non-Fermi-Liquid Behavior of Compressible States of Electrons on the Lowest Landau Level | cond-mat.mes-hall | Experiments show that at even denominator fractions (EDFs) ($\nu=1/2, 3/4,
3/2$,...) the two-dimensional electron gas in a strong magnetic field becomes
compressible, has no energy gap, and demonstrates the presence of an ostensible
Fermi surface. Since this phenomenon results from a minimization of the
interaction, ra... | physics |
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