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2022-01-30
Port Reconfigurable Phase-Change Optical Resonator
Active control and manipulation of electromagnetic waves are highly desirable for advanced photonic device technology, such as optical cloaking, active camouflage and information processing. Designing optical resonators with high ease-of-control and reconfigurability remains a open challenge thus far. Here we propose a...
2201.12800v1
2022-02-01
Pion axioproduction: The Delta resonance contribution
The process of pion axioproduction, $aN\to\pi N$, with an intermediate $\Delta$ resonance is analyzed using baryon chiral parturbation theory. The $\Delta$ resonance is included in two ways: First, deriving the $a\Delta N$-vertices, the axion is brought into contact with the resonance, and, second, taking the results o...
2202.00268v2
2022-03-01
Determination of atomic multiphoton ionization phases by trichromatic multichannel wave packet interferometry
We present a multichannel photoelectron interferometry technique based on trichromatic pulse shaping for unambiguous determination of quantum phases in multiphoton ionization (MPI) of potassium atoms. The colors of the laser field are chosen to produce three energetically separated photoelectron interferograms in the c...
2203.00323v2
2022-03-21
Computation of eigenfrequency sensitivities using Riesz projections for efficient optimization of nanophotonic resonators
Resonances are omnipresent in physics and essential for the description of wave phenomena. We present an approach for computing eigenfrequency sensitivities of resonances. The theory is based on Riesz projections and the approach can be applied to compute partial derivatives of the complex eigenfrequencies of any reson...
2203.11101v2
2022-06-22
Neolithic stone settlements as locally resonant metasurfaces
We study the dynamic surface response of neolithic stone settlements obtained with seismic ambient noise techniques near the city of Carnac in French Brittany. Surprisingly, we find that menhirs (neolithic human size standing alone granite stones) with an aspect ratio between 1 and 2 periodically arranged atop a thin l...
2206.10825v1
2022-12-26
On phase at a resonance in slow-fast Hamiltonian systems
We consider a slow-fast Hamiltonian system with one fast angular variable (a fast phase) whose frequency vanishes on some surface in the space of slow variables (a resonant surface). Systems of such form appear in the study of dynamics of charged particles in inhomogeneous magnetic field under influence of a high-frequ...
2212.13293v1
2023-04-03
Improved constraints on minimum length models with a macroscopic low loss phonon cavity
Many theories that attempt to formulate a quantum description of gravity suggest the existence of a fundamental minimum length scale. A popular method for incorporating this minimum length is through a modification of the Heisenberg uncertainty principle known as the generalised uncertainty principle (GUP). Experimenta...
2304.00688v2
2023-04-09
Beyond 5 GHz excitation of a ZnO-based high-overtone bulk acoustic resonator on SiC substrate
This work describes the fabrication and characterization of an Au/ZnO/Pt-based high-overtone bulk acoustic resonator (HBAR) on SiC substrates. We evaluate its microwave characteristics comparing with Si substrates for micro-electromechanical applications. Dielectric magnetron sputtering and an electron beam evaporator ...
2304.04286v1
2023-09-21
Simultaneous Resonant and Broadband Detection for Dark Sectors
Electromagnetic resonant systems, such as cavities or LC circuits, have emerged as powerful detectors for probing ultralight boson dark matter and high-frequency gravitational waves. However, the limited resonant bandwidth of conventional single-mode resonators, imposed by quantum fluctuations, necessitates numerous sc...
2309.12387v1
2024-01-08
Room-Temperature Plasmon-Assisted Resonant THz Detection in Single-layer Graphene Transistors
Frequency-selective or even frequency-tunable Terahertz (THz) photodevices are critical components for many technological applications that require nanoscale manipulation, control and confinement of light. Within this context, gate-tunable phototransistors based on plasmonic resonances are often regarded as the most pr...
2401.04005v1
2024-02-08
Extinction of guided light induced by coupled spiral meta-atom resonators at arbitrary order exceptional points
Exceptional points (EPs) in non-Hermitian systems can give rise to intriguing effects not available in conventional Hermitian systems due to their unusual properties. Using full-wave simulations, we investigate the scattering, absorption, and transmission of guided light at arbitrary order exceptional points in a non-H...
2402.06686v1
1999-08-24
Spin Dynamics of Rare Earth Ions in Phosphate Laser Glasses
The spin dynamics of rare earth ions (Er, Nd, Sm and Gd) in heavily doped phosphate glasses have been investigated using 31P NMR. Correlation times in the range 10^-2 to 10^-12 s have been obtained for temperatures between 4 K and 100 K. No evidence of spin-spin coupling between the ions has been found and spin relaxat...
9908333v1
2000-07-25
Spin-lattice relaxation in the mixed state of the high-$T_c$ cuprates: electronic spin-flip scattering versus spin-fluctuations
Recent experimental and theoretical studies have established that the spin-lattice relaxation rate, $1/T_1$, measured in nuclear magnetic resonance (NMR) experiments is a site-sensitive probe for the electronic spectrum in the mixed state of the high-$T_c$ cuprates. While some groups suggested that $1/T_1$ is solely de...
0007393v1
2001-07-10
Cu NQR study of host and guest spin dynamics in impurity-doped YBa2Cu4O8
We present the planar 63Cu nuclear spin-lattice relaxation study of impurity-doped YBa2(Cu1-xMx)4O8 (M=Ni, Zn) at T=4.2-300 K with Cu nuclear quadrupole resonance (NQR) spin-echo technique. In the light of an impurity-induced NQR relaxation theory, we estimated the host Cu nuclear spin-lattice relaxation time (T1)HOST,...
0107186v1
2002-09-24
Nonequilibrium spin fluctuations in single-electron transistors
We show that nonequilibrium spin fluctuations significantly influence the electronic transport in a single-electron transistor, when the spin relaxation on the island is slow compared to other relaxation processes, and when size effects play a role. To describe spin fluctuations we generalize the `orthodox' tunneling t...
0209559v1
2003-02-24
Detection of electrical spin injection by light-emitting diodes in top- and side-emission configuration
Detection of the degree of circular polarization of the electroluminescence of a light-emitting diode fitted with a spin injecting contact (a spin-LED) allows for a direct determination of the spin polarization of the injected carriers. Here, we compare the detection efficiency of (Al,Ga)As spin-LEDs fitted with a (Zn,...
0302477v1
2004-01-03
Spin-lattice relaxation rate of a magnetic impurity in the spin degenerate Anderson model
The renormalization group formalism was applied to calculate the spin-lattice relaxation rate of a well-defined magnetic moment in the neighborhood of a spin degenerate Anderson impurity. In the Kondo regime, the spin-lattice relaxation rate as a function of the temperature presents a peak at the Kondo temperature; for...
0401022v1
2005-05-02
Absence of spin superradiance in resonatorless magnets
A spin system is considered with a Hamiltonian typical of molecular magnets, having dipole-dipole interactions and a single-site magnetic anisotropy. In addition, spin interactions through the common radiation field are included. A fully quantum-mechanical derivation of the collective radiation rate is presented. An ef...
0505024v1
2006-05-08
Spin-orbit effects in GaAs quantum wells: Interplay between Rashba, Dresselhaus, and Zeeman interactions
The interplay between Rashba, Dresselhaus and Zeeman interactions in a quantum well submitted to an external magnetic field is studied by means of an accurate analytical solution of the Hamiltonian, including electron-electron interactions in a sum rule approach. This solution allows to discuss the influence of the spi...
0605199v1
2006-10-17
The spin state transition in LaCoO$_{3}$; revising a revision
Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-$L_{2,3}$ edge we reveal that the spin state transition in LaCoO$_{3}$ can be well described by a low-spin ground state and a triply-degenerate high-spin first excited state. From the temperature dependence of the spectral lineshapes we ...
0610457v1
2007-01-15
Decoherence induced by anisotropic hyperfine interaction in Si spin qubits
We study Si:P donor electron spin decoherence due to anisotropic hyperfine (AHF) interaction with the surrounding nuclear spin bath. In particular, we clarify the electron spin echo envelope modulation (ESEEM) in the Si:P system and the resonancelike contributions from nuclear spins in various shells away from the P at...
0701341v2
2004-09-12
Energy levels and decoherence properties of single electron and nuclear spins in a defect center in diamond
The coherent behavior of the single electron and single nuclear spins of a defect center in diamond and a 13C nucleus in its vicinity, respectively, are investigated. The energy levels associated with the hyperfine coupling of the electron spin of the defect center to the 13C nuclear spin are analyzed. Methods of magne...
0409067v1
2004-11-18
Entanglement Assisted Metrology
We propose a new approach to the measurement of a single spin state, based on nuclear magnetic resonance (NMR) techniques and inspired by the coherent control over many-body systems envisaged by Quantum Information Processing (QIP). A single target spin is coupled via the natural magnetic dipolar interaction to a large...
0411128v1
2007-07-09
Coherence of an optically illuminated single nuclear spin qubit
We investigate the coherence properties of individual nuclear spin quantum bits in diamond [Dutt et al., Science, 316, 1312 (2007)] when a proximal electronic spin associated with a nitrogen-vacancy (NV) center is being interrogated by optical radiation. The resulting nuclear spin dynamics are governed by time-dependen...
0707.1341v2
2007-10-11
Electrically Tunable Spin Polarization in a Carbon-Nanotube Spin Diode
We have studied the current through a carbon nanotube quantum dot with one ferromagnetic and one normal-metal lead. For the values of gate voltage at which the normal lead is resonant with the single available non-degenerate energy level on the dot, we observe a pronounced decrease in the current for one bias direction...
0710.2297v1
2008-11-25
Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors
We develop an understanding of the anomalous metal state of the parent compounds of recently discovered iron based superconductors starting from a strong coupling viewpoint, including orbital degrees of freedom. On the basis of an intermediate-spin (S=1) state for the Fe^{2+} ions, we derive a Kugel-Khomskii spin-orbit...
0811.4104v1
2009-01-05
Coherence and control of quantum registers based on electronic spin in a nuclear spin bath
We consider a protocol for the control of few-qubit registers comprising one electronic spin embedded in a nuclear spin bath. We show how to isolate a few proximal nuclear spins from the rest of the environment and use them as building blocks for a potentially scalable quantum information processor. We describe how coh...
0901.0444v1
2009-01-14
Ab-initio calculations of spin tunneling through an indirect barrier
We use a fully relativistic layer Green's functions approach to investigate spin-dependent tunneling through a symmetric indirect band gap barrier like GaAs/AlAs/GaAs heterostructure along [100] direction. The method is based on Linear Muffin Tin Orbitals and it is within the Density Functional Theory (DFT) in the Loca...
0901.2021v1
2009-02-19
Kondo screening suppression by spin-orbit interaction in quantum dots
We study the transport properties of a quantum dot embedded in an Aharonov-Bohm ring in the presence of spin-orbit interactions. Using a numerical renormalization group analysis of the system in the Kondo regime, we find that the competition of Aharonov-Bohm and spin-orbit dynamical phases induces a strong suppression ...
0902.3310v1
2009-03-11
Nanomechanical Detection of Itinerant Electron Spin Flip
Spin is an intrinsically quantum property, characterized by angular momentum. A change in the spin state is equivalent to a change in the angular momentum or mechanical torque. This spin-induced torque has been invoked as the intrinsic mechanism in experiments ranging from the measurements of angular momentum of photon...
0903.1894v1
2009-04-08
Architecture for high-sensitivity single-shot readout and control of the electron spin of individual donors in silicon
We describe a method to control and detect in single-shot the electron spin state of an individual donor in silicon with greatly enhanced sensitivity. A silicon-based Single-Electron Transistor (SET) allows for spin-dependent tunneling of the donor electron directly into the SET island during the read-out phase. Simula...
0904.1271v4
2009-12-25
Faraday Rotation with Single Nuclear Spin Qubit in a High-Finesse Optical Cavity
When an off-resonant light field is coupled with atomic spins, its polarization can rotate depending on the direction of the spins via a Faraday rotation which has been used for monitoring and controlling the atomic spins. We observed Faraday rotation by an angle of more than 10 degrees for a single 1/2 nuclear spin of...
0912.4948v3
2011-04-22
High spin states of cation vacancies in GaP, GaN, AlN, BN, ZnO and BeO: A first principles study
High spin states of cation vacancies in GaP, GaN, AlN, BN, ZnO and BeO were analyzed by first principles calculations. The spin-polarized vacancy-induced level is located in the band gap in GaP, ZnO and BeO. In the nitrides, the stronger exchange coupling forces the vacancy states to be resonant with valence bands, for...
1104.4420v1
2012-03-05
Coherent multi-flavour spin dynamics in a fermionic quantum gas
Microscopic spin interaction processes are fundamental for global static and dynamical magnetic properties of many-body systems. Quantum gases as pure and well isolated systems offer intriguing possibilities to study basic magnetic processes including non-equilibrium dynamics. Here, we report on the realization of a we...
1203.0948v1
2012-04-02
Spin dynamics of S-state ions in the filled skutterudites La1-xRx$Pt4Ge12 (R= Gd, Eu)
A detailed study of the spin dynamics of the S-state ions Gd3+ and Eu2+ in the filled skutterudites La1-xRxPt4Ge12 (R= Gd, Eu) is reported. The spin dynamics is investigated directly by means of Gd3+ and Eu2+ electron spin resonance (ESR), performed at X-band (~ 9.4 GHz) and Q-band (~ 34 GHz) frequencies in the tempera...
1204.0481v1
2012-04-13
High resolution spectroscopy of single NV defects coupled with nearby $^{13}$C nuclear spins in diamond
We report a systematic study of the hyperfine interaction between the electron spin of a single nitrogen-vacancy (NV) defect in diamond and nearby $^{13}$C nuclear spins, by using pulsed electron spin resonance spectroscopy. We isolate a set of discrete values of the hyperfine coupling strength ranging from 14 MHz to 4...
1204.2947v1
2012-05-25
Study of two-spin entanglement in singlet states
We study the entanglement properties of two-spin subsystems in spin-singlet states. The average entanglement between two spins is maximized in a single valence-bond (VB) state. On the other hand, $E_v^2$ (the average entanglement between a subsystem of two spins and the rest of the system) can be maximized through a ho...
1205.5667v3
2012-08-30
Generation of spin-polarized current using multi-terminated quantum dot with spin-orbit interaction
We theoretically examine generation of spin-polarized current using multi-terminated quantum dot with spin-orbit interaction. First, a two-level quantum dot is analyzed as a minimal model, which is connected to $N$ ($\ge 2$) external leads via tunnel barriers. When an unpolarized current is injected to the quantum dot ...
1208.6084v1
2013-01-14
Spin coherent states in NMR quadrupolar system: experimental and theoretical applications
Working with nuclear magnetic resonance (NMR) in quadrupolar spin systems, in this paper we transfer the concept of atomic coherent state to the nuclear spin context, where it is referred to as pseudo-nuclear spin coherent state (pseudo-NSCS). Experimentally, we discuss the initialization of the pseudo-NSCSs and also t...
1301.2862v1
2013-05-03
Dependence of spin pumping spin Hall effect measurements on layer thicknesses and stacking order
Voltages generated from inverse spin Hall and anisotropic magneto-resistance effects via spin pumping in ferromagnetic (F)/non-magnetic (N) bilayers are investigated by means of a broadband ferromagnetic resonance approach. Varying the non-magnetic layer thickness enables the determination of the spin diffusion length ...
1305.0745v2
2013-05-31
Enhanced hyperfine-induced spin dephasing in a magnetic-field gradient
Magnetic-field gradients are important for single-site addressability and electric-dipole spin resonance of spin qubits in semiconductor devices. We show that these advantages are offset by a potential reduction in coherence time due to the non-uniformity of the magnetic field experienced by a nuclear-spin bath interac...
1305.7506v2
2013-07-06
Probing the Spin Pumping Mechanism: Exchange Coupling with Exponential Decay in Y3Fe5O12/barrier/Pt Heterostructures
Ferromagnetic resonance driven spin pumping of pure spin currents from a ferromagnet into a nonmagnetic material promises new spin-functional devices with low energy consumption. The mechanism of spin pumping is under intense investigation and it is widely believed that exchange interaction between the ferromagnet and ...
1307.1816v2
2013-10-13
Optically-driven nuclear-spin-selective Rabi oscillations of single electron spins in diamond
Optically-driven Rabi oscillations of single electron spins in a diamond nitrogen vacancy center are realized with two Raman-resonant optical pulses that are detuned from the respective dipole optical transitions. The Rabi oscillations are nuclear-spin selective and are robust against rapid decoherence of the underlyin...
1310.3525v1
2013-10-24
Dynamics in spinor condensates controlled by a microwave dressing field
We experimentally study spin dynamics in a sodium antiferromagnetic spinor condensate with off-resonant microwave pulses. In contrast to a magnetic field, a microwave dressing field enables us to explore rich spin dynamics under the influence of a negative net quadratic Zeeman shift $q_{\rm net}$. We find an experiment...
1310.6785v1
2013-11-26
Electrically and mechanically tunable electron spins in silicon carbide color centers
The electron spins of semiconductor defects can have complex interactions with their host, particularly in polar materials like SiC where electrical and mechanical variables are intertwined. By combining pulsed spin resonance with ab-initio simulations, we show that spin-spin interactions within SiC neutral divacancies...
1311.6832v1
2013-11-28
Dynamic Spin Fluctuations at $T\rightarrow 0$ in a Spin-1/2 Ferromagnetic Kagome Lattice
We report magnetization, electron spin resonance (ESR), and muon spin relaxation ($\mu $SR) measurements on single crystals of the $S=1/2$ (Cu$% ^{+2}$) kagom\'{e} compound Cu(1,3-benzendicarboxylate). The $\mu $SR is carried to temperatures as low as 45 mK. The spin Hamiltonian parameters are determined from the analy...
1311.7411v1
2013-12-10
Optical signatures of silicon-vacancy spins in diamond
Colour centres in diamond have emerged as versatile tools for solid-state quantum technologies ranging from quantum information to metrology, where the nitrogen-vacancy centre is the most studied to-date. Recently, this toolbox has expanded to include different materials for their nanofabrication opportunities, and nov...
1312.2997v1
2013-12-17
High-fidelity adiabatic inversion of a $^{31}\mathrm{P}$ electron spin qubit in natural silicon
The main limitation to the high-fidelity quantum control of spins in semiconductors is the presence of strongly fluctuating fields arising from the nuclear spin bath of the host material. We demonstrate here a substantial improvement in single-qubit gate fidelities for an electron spin qubit bound to a $^{31}$P atom in...
1312.4647v1
2013-12-17
Low energy magnetic excitations in the spin-orbital Mott insulator Sr$_2$IrO$_4$
We report a high-field electron spin resonance study in the sub-THz frequency domain of a single crystal of Sr$_2$IrO$_4$ that has been recently proposed as a prototypical spin-orbital Mott insulator. In the antiferromagnetically (AFM) ordered state with noncollinear spin structure that occurs in this material at $T_{\...
1312.4847v2
2013-12-30
Indirect control of spin precession by electric field via spin-orbit coupling
The spin-orbit coupling (SOC) can mediate electric-dipole spin resonance (EDSR) in an a.c. electric field. In this letter, the EDSR is essentially understood as an spin precession under an effective a.c. magnetic field induced by the SOC in the reference frame, which is exactly following the classical trajectory of the...
1312.7635v3
2014-01-06
The empirical Monod-Beuneu relation of spin-relaxation revisited for elemental metals
Monod and Beuneu [Monod and Beuneu, Phys. Rev. B 19, 911 (1979)] established the validity of the Elliott-Yafet theory for elemental metals through correlating the experimental electron spin resonance line-width with the so-called spin-orbit admixture coefficients and the momentum-relaxation theory. The spin-orbit admix...
1401.1048v1
2014-03-11
Spin squeezing in an ensemble of quadrupolar nuclei NMR system
We have characterized spin-squeezed states produced at a temperature of $26^\circ{\mathrm C}$ on a Nuclear Magnetic Resonance (NMR) quadrupolar system. The implementation is carried out in an ensemble of $^{133}$Cs nuclei with spin $I=7/2$ of a lyotropic liquid crystal sample. We identify the source of spin squeezing d...
1403.2706v1
2014-08-11
Hole spin dynamics and hole $g$ factor anisotropy in coupled quantum well systems
Due to its p-like character, the valence band in GaAs-based heterostructures offers rich and complex spin-dependent phenomena. One manifestation is the large anisotropy of Zeeman spin splitting. Using undoped, coupled quantum wells (QWs), we examine this anisotropy by comparing the hole spin dynamics for high- and low-...
1408.2360v1
2014-09-02
Quantum spin coherence in halogen-modified Cr$_7$Ni molecular nanomagnets
Among the factors determining the quantum coherence of the spin in molecular magnets is the presence and the nature of nuclear spins in the molecule. We have explored modifying the nuclear spin environment in Cr$_7$Ni-based molecular nanomagnets by replacing hydrogen atoms with deuterium or the halogen atoms, fluorine ...
1409.0821v2
2014-09-16
Phonon-modulated magnetic interactions and spin Tomonaga-Luttinger liquid in the p-orbital antiferromagnet CsO2
The magnetic response of antiferromagnetic CsO2, coming from the p-orbital S=1/2 spins of anionic O2- molecules, is followed by 133Cs nuclear magnetic resonance across the structural phase transition occuring at Ts1=61 K on cooling. Above Ts1, where spins form a square magnetic lattice, we observe a huge, nonmonotonic ...
1409.4818v2
2014-09-22
Donor Spin Qubits in Ge-based Phononic Crystals
We propose qubits based on shallow donor electron spins in germanium. Spin-orbit interaction for donor spins in germanium is in many orders of magnitude stronger than in silicon. In a uniform bulk material it leads to very short spin lifetimes. However the lifetime increases dramatically when the donor is placed into a...
1409.6285v1
2014-11-28
Position-dependent spin-orbit coupling for ultracold atoms
We theoretically explore atomic Bose-Einstein condensates (BECs) subject to position-dependent spin-orbit coupling (SOC). This SOC can be produced by cyclically laser coupling four internal atomic ground (or metastable) states in an environment where the detuning from resonance depends on position. The resulting spin-o...
1411.7813v2
2015-01-19
Effect of Exchange Interaction on Magnetic Thermal Fluctuation and Spin Susceptibility
The expression of the thermal fluctuation parameter in the stochastic Landau-Lifshitz-Gilbert equation has been derived from a fundamental quantum theory of spins and phonons, in which the exchange interaction between nearest atoms has been included. Our studies show that the thermal fluctuation decreases exponentially...
1501.04503v2
2015-02-13
Coherent heteronuclear spin dynamics in an ultracold spin-1 mixture
We report the observation of coherent heteronuclear spin dynamics driven by inter-species spin-spin interaction in an ultracold spinor mixture, which manifests as periodical and well correlated spin oscillations between two atomic species. In particular, we investigate the magnetic field dependence of the oscillations ...
1502.03867v1
2015-02-13
Antiferromagnet-Mediated Spin Transfer Between Metal and Ferromagnet
We develop a theory for spin transported by coherent Neel dynamics through an antiferromagnetic insulator coupled to a ferromagnetic insulator on one side and a current-carrying normal metal with strong spin-orbit coupling on the other. The ferromagnet is considered within the mono-domain limit and we assume its coupli...
1502.04128v1
2015-04-03
Single-shot measurement of transient nuclear magnetization with spin-noise spectroscopy in n-GaAs microcavities
We exploit spin noise spectroscopy (SNS) to directly observe build-up of dynamic nuclear polarization and relaxation of a perturbed nuclear spin-system to its equilibrium state in a single-shot experiment. The SNS experiments were performed on a layer of bulk $n$-type GaAs embedded into a high-finesse microcavity with ...
1504.00799v1
2015-05-15
Direct detection of pure spin-current by x-ray pump-probe measurements
By synchronizing a microwave waveform with the synchrotron x-ray pulses, we use the ferromagnetic resonance (FMR) of the Py (Ni81Fe19) layer in a Py/Cu/Cu75Mn25/Cu/Co multilayer to pump a pure spin current into the Cu75Mn25 spacer layer, and then directly probe the spin current in the Cu75Mn25 layer by a time-resolved ...
1505.03959v2
2015-07-06
Nuclear spin noise in NMR revisited
The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite, preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR ...
1507.01398v2
2015-08-11
Suppression of the impurity-induced local magnetism by the opening of a spin pseudogap in Ni-doped Sr$_2$CuO$_3$
The $S=1/2$ antiferromagnetic Heisenberg spin chain compound Sr$_2$CuO$_3$ doped with $1 \%$ and $2 \%$ of Ni impurities has been studied by means of $^{63}$Cu nuclear magnetic resonance. A strong decrease of the spin-lattice relaxation rate $T_1^{-1}$ at low temperatures points toward a spin gap, while a stretching ex...
1508.02529v1
2015-08-26
Multistability and spin diffusion enhanced lifetimes in dynamic nuclear polarization in a double quantum dot
The control of nuclear spins in quantum dots is essential to explore their many-body dynamics and exploit their prospects for quantum information processing. We present a unique combination of dynamic nuclear spin polarization and electric-dipole-induced spin resonance in an electrostatically defined double quantum dot...
1508.06522v2
2015-09-03
Long-lived states with well-defined spins in spin-$1/2$ homogeneous Bose gases
Many-body eigenfunctions of the total spin operator can be constructed from the spin and spatial wavefunctions with non-trivial permutation symmetries. Spin-dependent interactions can lead to relaxation of the spin eigenstates to the thermal equilibrium. A mechanism that stabilizes the many-body entangled states is pro...
1509.01264v3
2016-01-20
Enhanced photonic spin Hall effect with subwavelength topological edge states
Photonic structures offer unique opportunities for controlling light-matter interaction, including the photonic spin Hall effect associated with the transverse spin-dependent displacement of light that propagates in specially designed optical media. However, due to small spin-orbit coupling, the photonic spin Hall effe...
1601.05264v1
2016-04-10
Measurement of spin coherence using Raman scattering
Ramsey interferometry provides a natural way to determine the coherence time of most qubit systems. Recent experiments on quantum dots however, demonstrated that dynamical nuclear spin polarization can strongly influence the measurement process, making it difficult to extract the $T_2^*$ coherence time using optical Ra...
1604.02685v1
2016-04-27
Spin exchange collision mixing of the K and Rb ac Stark shifts
In a hybrid pumping alkali vapor cell that both K and Rb are filled, K atom spins are optically pumped by laser and Rb atom spins are polarized by the K spins through spin exchange. We find that the AC Stark shift of the Rb atoms is composed of not only the AC Stark shift of the Rb atoms caused by the far off resonant ...
1604.07908v1
2016-05-16
Spin-polarization in the vicinity of quantum point contact with spin-orbit interaction
We have developed a novel technique for detection of spin polarization with a quantum dot weakly coupled to the objective device. The disturbance to the object in this technique is very small since the detection is performed through sampling of single electrons in the object with very slow rate. We have applied the met...
1605.04685v1
2016-07-26
Spin-orbit signatures in the dynamics of singlet-triplet qubits in double quantum dots
We characterize numerically and analytically the signatures of the spin-orbit interaction in a two-electron GaAs double quantum dot in the presence of an external magnetic field. In particular, we obtain the return probability of the singlet state by simulating Landau-Zener voltage detuning sweeps which traverse the si...
1607.07852v3
2016-09-07
Spin excitations in the quasi-two-dimensional charge-ordered insulator $α$-(BEDT-TTF)$_2$I$_3$ probed via $^{13}$C NMR
The spin excitations from the nonmagnetic charge-ordered insulating state of $\alpha$-(BEDT-TTF)$_2$I$_3$ at ambient pressure have been investigated by probing the static and low-frequency dynamic spin susceptibilities via site-selective nuclear magnetic resonance at $^{13}$C sites. The site-dependent values of the shi...
1609.01906v1
2016-10-07
Spin-orbit coupling controlled $J=3/2$ electronic ground state in 5$d^{3}$ oxides
Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Discovering new spin-orbit entangled ground states and emergent phases of matter requires both experimentally probing the relevant energy scales and applying suitable theoretical models. Here we re...
1610.02375v1
2017-07-02
Dynamics of one-dimensional electrons with broken spin-charge separation
Spin-charge separation is known to be broken in many physically interesting one-dimensional (1D) and quasi-1D systems with spin-orbit interaction because of which spin and charge degrees of freedom are mixed in collective excitations. Mixed spin-charge modes carry an electric charge and therefore can be investigated by...
1707.00316v3
2017-08-14
Spin-resolved electronic structure of ferroelectric α-GeTe and multiferroic Ge1-xMnxTe
Germanium telluride features special spin-electric effects originating from spin-orbit coupling and symmetry breaking by the ferroelectric lattice polarization, which opens up many prospectives for electrically tunable and switchable spin electronic devices. By Mn doping of the {\alpha}-GeTe host lattice, the system be...
1708.04104v1
2017-11-17
Measuring anisotropic spin relaxation in graphene
We compare different methods to measure the anisotropy of the spin-lifetime in graphene. In addition to out-of-plane rotation of the ferromagnetic electrodes and oblique spin precession, we present a Hanle experiment where the electron spins precess around either a magnetic field perpendicular to the graphene plane or ...
1711.06472v2
2017-12-01
Coherent spin dynamics of ytterbium ions in yttrium orthosilicate
We investigate the electron and nuclear spin coherence properties of ytterbium ($\mathrm{Yb}^{3+}$) ions with non-zero nuclear spin, within an yttrium orthosilicate (Y$_2$SiO$_5$) crystal, with a view to their potential application in quantum memories or repeaters. We find electron spin-lattice relaxation times are max...
1712.00435v1
2017-12-14
Synthesis of antisymmetric spin exchange interaction and entanglement generation with chiral spin states in a superconducting circuit
We have synthesized the anti-symmetric spin exchange interaction (ASI), which is also called the Dzyaloshinskii-Moriya interaction, in a superconducting circuit containing five superconducting qubits connected to a bus resonator, by periodically modulating the transition frequencies of the qubits with different modulat...
1712.05261v2
2017-12-25
Coherent states in Magnetic Resonance
In NMR experiments, interaction of quantized radio-frequency (rf) field leads to entanglement of nuclear spin with the electromagnetic field. In an entangled state, the nuclear spins are depolarized with no net magnetization, which cannot give a detectable signal in inductive detection. We show that when the electromag...
1712.09060v1
2018-01-03
Negative spin-Hall angle and anisotropic spin-orbit torques in epitaxial IrMn
A spin-torque ferromagnetic resonance study is performed in epitaxial $\mathrm{Fe / Ir_{15}Mn_{85}}$ bilayers with different Fe thicknesses. We measure a negative spin-Hall angle of a few percent in the antiferromagnetic IrMn in contrast to previously reported positive values. A large spin-orbit field with Rashba symme...
1801.01065v1
2018-05-14
Electric field control of spins in molecular magnets
Coherent control of individual molecular spins in nano-devices is a pivotal prerequisite for fulfilling the potential promised by molecular spintronics. By applying electric field pulses during time-resolved electron spin resonance measurements, we measure the sensitivity of the spin in several antiferromagnetic molecu...
1805.05256v2
2018-05-19
Optically driven spin pumping mediating collective magnetization dynamics in a spin valve structure
We demonstrate spin pumping, i.e. the generation of a pure spin current by precessing magnetization, without application of microwave radiation commonly used in spin pumping experiments. We use femtosecond laser pulses to simultaneously launch the magnetization precession in each of two ferromagnetic layers of a Galfen...
1805.07669v1
2017-05-10
Interplay of valley polarization and dynamic nuclear polarization in 2D transition metal dichalcogenides
The interplay of Ising spin-orbit coupling and non-trivial band topology in transition metal dichalcogenides (TMDs) produces anomalous transport and optical properties that are very different from a regular 2D electron gas. The spin-momentum locking of optically excited carriers near a valley point can give rise to an ...
1705.03909v2
2017-05-24
Spin-singlet superconductivity in doped topological crystalline insulator Sn_{0.96}In_{0.04}Te
The In-doped topological crystalline insulator Sn_{1-x}In_xTe is a candidate for a topological superconductor, where pseudo-spin-triplet state has been proposed. To clarify the spin symmetry of Sn_{1-x}In_xTe, we perform ^{125}Te-nuclear magnetic resonance (NMR) measurements in polycrystalline samples with 0< x <0.15. ...
1705.08636v2
2017-05-30
Fast optical control of spin in semiconductor interfacial structures
We report on a picosecond-fast optical removal of spin polarization from a self-confined photo-carrier system at an undoped GaAs/AlGaAs interface possessing superior long-range and high-speed spin transport properties. We employed a modified resonant spin amplification technique with unequal intensities of subsequent p...
1705.10627v1
2018-02-08
Coherent control of solid state nuclear spin nano-ensembles
Detecting and controlling nuclear spin nano-ensembles is crucial for the further development of nuclear magnetic resonance (NMR) spectroscopy and for the emerging solid state quantum technology. Here we present the fabrication of a $\approx$ 1 nanometre thick diamond layer consisting of $^{13}$C nuclear spins doped wit...
1802.02921v1
2018-08-01
Neutrino spin and spin-flavour oscillations in transversal matter currents with standard and non-standard interactions
After a brief history of two known types of neutrino mixing and oscillations, including neutrino spin and spin-flavour oscillations in the transversal magnetic field, we perform systematic study of a new phenomenon of neutrino spin and spin-flavour oscillations engendered by the transversal matter currents on the bases...
1808.00302v2
2018-08-08
Analog Quantum Simulation of Extremely Sub-Ohmic Spin-Boson Models
We propose a scheme for the quantum simulation of sub-Ohmic spin--boson models by color centers in free-standing hexagonal boron nitride (h-BN) membranes. The electronic spin of a color center that couples to the membrane vibrational spectrum constitute the physical model. The spin-motion coupling is provided by an ext...
1808.02916v1
2019-02-10
Spin asymmetry in single pion production induced by weak interactions of neutrinos with polarized nucleons
The single pion production (SPP) in the charged-current neutrino (antineutrino) scattering off the polarized nucleon is discussed. The spin asymmetry is predicted within two approaches. The spin polarizations of the target nucleon that are longitudinal and perpendicular to the neutrino momentum are considered. It is sh...
1902.03671v2
2020-08-09
Reduction of surface spin-induced electron spin relaxations in nanodiamonds
Nanodiamonds (NDs) hosting nitrogen-vacancy (NV) centers are promising for applications of quantum sensing. Long spin relaxation times ($T_1$ and $T_2$) are critical for high sensitivity in quantum applications. It has been shown that fluctuations of magnetic fields due to surface spins strongly influences $T_1$ and $T...
2008.03832v1
2016-12-06
Spin-Hall Torques Generated by Rare-Earth (Lanthanide) Thin Films
We report an initial experimental survey of spin-Hall torques generated by the rare-earth metals Gd, Dy, Ho, and Lu, along with comparisons to first-principles calculations of their spin Hall conductivities. Using spin torque ferromagnetic resonance (ST-FMR) measurements and DC-biased ST-FMR, we estimate lower bounds f...
1612.01927v1
2016-12-21
Spin transitions driven by electric dipole spin resonance in fluorinated single- and bilayer-graphene quantum dots
Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene are considered as well as electrostatic electron traps induced in bilayer graphene. The stationary states are obtained within the tight-binding approach and are...
1612.07001v1
2017-02-17
Spin-pumping through a varying-thickness MgO interlayer in Fe/Pt system
The spin-pumping mechanism is probed through a tunnelling MgO interlayer in Fe/Pt bilayers. We show by ferromagnetic resonance technique and spin-pumping experiments that spin currents can tunnel through the MgO interlayer for thickness up to 2~{nm} and can produce significant voltages in the Pt layer. The electrical d...
1702.05298v1
2017-10-24
Electrical spin driving by $g$-matrix modulation in spin-orbit qubits
In a semiconductor spin qubit with sizable spin-orbit coupling, coherent spin rotations can be driven by a resonant gate-voltage modulation. Recently, we have exploited this opportunity in the experimental demonstration of a hole spin qubit in a silicon device. Here we investigate the underlying physical mechanisms by ...
1710.08690v2
2017-10-26
Itinerant spin fluctuations in iron-based superconductors
Multiband systems, which possess a wide parameter space, allow to explore a variety of competing ground states. Bright examples are the Fe-based pnictides and chalcogenides, which demonstrate metallic, superconducting, and various magnetic phases. Here I discuss only one of the many interesting topics, namely, spin flu...
1710.09888v1
2019-03-14
Electrical control of spin mixing conductance in a Y$_3$Fe$_5$O$_{12}$/Platinum bilayer
We report a tunable spin mixing conductance, up to $\pm 22\%$, in a Y${}_{3}$Fe${}_{5}$O${}_{12}$/Platinum (YIG/Pt) bilayer.This control is achieved by applying a gate voltage with an ionic gate technique, which exhibits a gate-dependent ferromagnetic resonance line width. Furthermore, we observed a gate-dependent spin...
1903.05865v1
2020-09-03
Odd-spin glueballs, AdS/QCD and information entropy
Odd-spin glueballs in the dynamical AdS/QCD model are scrutinized, in the paradigm of the configurational entropy (CE). Configurational-entropic Regge trajectories, that relate the CE underlying odd-spin glueballs to their mass spectra and spin, are then engendered. They predict the mass spectra of odd-spin glueballs, ...
2009.01890v2
2020-09-28
Determination of spin-orbit torques by thickness-dependent spin-orbit torque FMR measurement
Current induced spin-orbit torques (SOTs) in Fe/Pt bilayers have been investigated utilizing the spin-orbit torque ferromagnetic resonance (SOT-FMR) measurement. Characterization of thin films with different thicknesses indicates existence of a sizable field-like spin-orbit torque competing with the Oersted field induc...
2009.13162v2
2020-11-12
Edge states in quantum spin chains: the interplay among interaction, gradient magnetic field and Floquet engineering
We explore the edge defects induced by spin-spin interaction in a finite paradigmatic Heisenberg spin chain. By introducing a gradient magnetic field and a periodically-modulated spin-exchange strength, the resonance between modulation frequency and magnetic field gradient can also induce asymmetric defects at the edge...
2011.06164v4
2019-07-13
Ab initio modelling of spin relaxation lengths in disordered graphene nanoribbons†
The spin-dependent transport properties of armchair graphene nanoribbons in the presence of extrinsic spin-orbit coupling induced by a random distribution of Nickel adatoms is studied. By combining a recursive Green's function formalism with density functional theory, we explore the influence of ribbon length and metal...
1907.05979v1