Controllable Spin Polarization of Charge Current by Rashba Spin Orbital Coupling

We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic fourterminal device of cross structure by using the inverse spin hall effect. The scattering region of device is a two-dimensional electron gas （2DEG） with Rashba spin orbital interaction （RSOI）, one of lead is ferromagnetic metal and other three leads are spin-degenerate normal metals. By using Landauer-Biittiker formalism, we found that when a longitudinal charge current flows through 2DEG scattering region from FM lead by external bias, the transverse current can be either a pure spin current or full-polarized charge current due to the combined effect of spin hall effect and its inverse process, and the polarization of this transverse current can be easily controlled by several device parameters such as the Fermi energy, ferromagnetic magnetization, and the RSOI constant. Our method may pave a new way to control the spin polarization of a charge current.     

Orbit–orbit interaction and photonic orbital Hall effect in reflection of a light beam

We examine the orbit-orbit interaction when a paraxial beamwith intrinsic orbital angular momentum （IOAM） reflects at an air-glass interface. The orbital-dependent splitting of the beam intensity distribution arises due to the interaction between IOAM and extrinsic orbital angular momentum （EOAM）. In addition, we find that the beam centroid shows an orbital-dependent rotation when seen along the propagation axis. However, the motion of the beam centroid related to the orbit-orbit interaction undergoes a straight line trajectory with a small angle inclining from the propagation axis. Similar to a previously developed spin-dependent splitting in the photonic spin Hall effect, the orbital-dependent splitting could lead to the photonic orbital Hall effect.     

Noncommutative Quantum Hall Effect of Bilayer Systems

In this paper we study the bilayer quantum Hall （QH） effect on a noncommutative phase space （NCPS）. By using perturbation theory, we calculate the energy spectrum, eigenfunction, Hall current, and Hall conductivity of the bilayer QH system, and express them in terms of noncommutative parameters θ and θ^-, respectively. In our calculation, we assume that these parameters vary from laver to laver.     

Finite size effects on helical edge states in HgTe quantum wells with the spin orbit coupling due to bulk- and structure-inversion asymmetries

There is a quantum spin Hall state in the inverted HgTe quantum well, characterized by the topologically protected gapless helical edge states lying within the bulk gap. It has been found that for a strip of finite width, the edge states on the two sides can couple together to produce a gap in the spectrum. The phenomenon is called the finite size effect in quantum spin Hall systems. In this paper, we investigate the effects of the spin-orbit coupling due to bulk- and structure-inversion asymmetries on the finite size effect in the HgTe quantum well by means of the numerical diagonalization method. When the bulk-inversion asymmetry is taken into account, it is shown that the energy gap Eg of the edge states due to the finite size effect features an oscillating exponential decay as a function of the strip width of the HgTe quantum well. The origin of this oscillatory pattern on the exponential decay is explained. Furthermore, if the bulk- and structure-inversion asymmetries are considered simultaneously, the structure-inversion asymmetry will induce a shift of the energy gap Eg closing point. Finally, based on the roles of the bulk- and structure-inversion asymmetries on the finite size effects, a way to realize the quantum spin Hall field effect transistor is proposed.     

An Extended Extrinsic Mechanism for Anomalous Hall Effect

The extrinsic mechanism for anomalous Hall effect in ferromagnets is extended to include the contributions both from spin-orbit-dependent impurity scattering and from the spin-orbit coupling induced by external electric fields. The results obtained suggest that, within the framework of the extrinsic mechanisms, the anomalous Hall current in a ferromagnet may also contain a substantial amount of dissipationless contribution independent of impurity scattering. After the contribution from the spin-orbit coupling induced by external electric fields is included, the total anomalous Hall conductivity is about two times larger than that due to soin-orbit dependent impurity scatterings.     

Analytical treatment of the nonlinear electron cloud effect and the combined effects with beam-beam and space charge nonlinear forces in storage rings

In this paper we treat first some nonlinear beam dynamics problems in storage rings, such as beam dynamic apertures due to magnetic multipoles, wiggles, beam-beam effects, nonlinear space charge effect, and then nonlinear electron cloud effect combined with beam-beam and space charge effects, analytically. This analytical treatment is applied to BEPC II. The corresponding analytical expressions developed in this paper are useful both in understanding the physics behind these problems and also in making practical quick hand estimations.     

Quantitative analysis of the self-absorption and reemission effects on the emission spectrum of photoluminescence in right-angle excitation–detection configuration

A theoretical approach based on differential radiative transport is proposed to quantitatively analyze the selfabsorption and reemission effects on the emission spectrum for right angle excitation–detection photoluminescence measurements,and the wavelength dependence of the reemission effect is taken into account.Simulations and experiments are performed using rhodamine 6G solutions in ethanol as model samples.It is shown that the self-absorption effect is the dominant effect on the detected spectrum by inducing pseudo red-shift and reducing total intensity;whereas the reemission effect partly compensates for signal decrease and also results in an apparent signal gain at the wavelengths without absorption.Both effects decrease with the decrease in the sample concentration and the propagation distance of the emission light inside the sample.We therefore suggest that diluted solutions are required for accurate photoluminescence spectrum measurements and photoluminescence-based measurements.     

Quantum Anti-Zeno Effect in Artificial Quantum Systems

In this paper, we study a quantum anti-Zeno effect （QAZE） purely induced by repetitive measurements for an artificial atom interacting with a structured bath. This bath can be artificially realized with coupled resonators in one dimension and possesses photonic band structure like Bloeh electron in a periodic potential. In the presence of repetitive measurements, the pure QAZE is discovered as the observable decay is not negligible even for the atomic energy level spacing outside of the energy band of the artificial bath. If there were no measurements, the decay would not happen outside of the band. In this sense, the enhanced decay is completely induced by measurements through the relaxation channels provided by the bath. Besides, we also discuss the controversial golden rule decay rates originated from the van Hove＇s singularities and the effects of the counter-rotating terms.     

Electric-Current-Induced Heat Generation in Kondo Regime

Using the nonequilibrium Green＇s function technique, we investigate the current induced heat generation in Kondo regime. The Kondo effect influences the heat generation significantly. In the curve of heat generation versus the bias, a negative differential of the heat generation is exhibited. The symmetry of the heat generation is destroyed by the strong electron-electron interaction and the electron-phonon interaction.     

Nonlinear spectroscopy of barium in parallel electric and magnetic fields

We report on the experimental spectral observations of barium in parallel electric and magnetic fields. The laser pulse is linearly polarized along or perpendicular to the fields, leading to the states m = 0 and the states m = -t-1 populated, respectively, by one photon excitation. By sweeping the electric field, we observe the linear and nonlinear splitting of the diamagnetic spectrum as the electric field increases. The spectral anticrossing is induced by the atomic core effect. The Stark spectrum also shows an obvious nonlinear quadratic behavior when the applied magnetic field varies strongly. All spectra are well explained by the full quantum calculation after taking the quantum defect effects of the channel ns up to nf into account.     

Tunneling of Bose-Einstein condensate and interference effect in a harmonic trap with a Gaussian energy barrier

The tunneling effect of Bose-Einstein condensate (BEC) in a harmonic trap with a Gaussian energy barrier is studied in this paper. The initial condensate evolves into two separate moving condensates after the tunneling time under certain conditions. The interference pattern between the two moving condensates is given as a comparison and as a further demonstration of the existence of the global phase.     

Multiferroicity in B-site ordered double perovskite Y2MnCrO6

Double perovskite manganite Y2MnCrO6 ceramic Novel multiferroic properties are displayed with respect is synthesized and its multiferroic properties are investigated. to other multiferroics, such as high ferroelectric phase transi- tion temperature, and the coexistence of ferrimagnetism and ferroelectricity. Moreover, the ferroelectric polarization of Y2MnCrO6 below the magnetic phase temperature can be effectively tuned by an external magnetic field, showing a re- markable magnetoelectric effect. These results open an effective avenue to explore magnetic multiferroics with spontaneous magnetization and ferroelectricity, as well as a high ferroelectric transition temperature.     

Anomalous Kondo-Switching Effect of a Spin-Flip Quantum Dot Embedded in an Aharonov-Bohm Ring

We theoretically investigate the Kondo effect of a quantum dot embedded in a mesoscopic Aharonov-Bohm （AIR） ring in the presence of the spin flip processes by means of the one-impurity Anderson Hamiltonian. Based on the slave-boson mean-field theory, we find that in this system the persistent current （PC） sensitively depends on the parity and size of the AB ring and can be tuned by the spin-flip scattering （R）. In the small AB ring, the PC is suppressed due to the enhancing R weakening the Kondo resonance. On the contrary, in the large AB ring, with R increasing, the peak of PC firstly moves up to max-peak and then down. Especially, the PC phase shift of π appears suddenly with the proper value of R, implying the existence of the anomalous Kondo effect in this system. Thus this system may be a carldidate for quantum switch.     

Self-biased magnetoelectric responses in magnetostrictive/piezoelectric composites with different high-permeability alloys

We comparatively investigate the influence of various high-permeability alloys on the hysteretic and remanent res- onant magnetoelectric （ME） response in a composite of magnetostrictive nickel （Ni） and piezoelectric Pb（Zrl_x, Tix）O3 （PZT）. In order to implement this comparative research, Co-based amorphous alloy （CoSiB）, Fe-based nanocrystalline alloy （FeCuNbSiB） and Fe-based amorphous alloy （FeSiB） are used according to different magnetostriction （2s） and saturation magnetization （μtoMs） characteristics. The bending and longitudinal resonant ME voltage coefficients （αME,b and αME,1） are observed comparatively for CoSiB/Ni/PZT, FeCuNbSiB/Ni/PZT, and FeSiB/Ni/PZT composites. The experimental data indicate that the FeSiB/Ni/PZT composite has the largest remanent self-biased aME,b and aME,1 due to the largest magnetic grading of λs and μ0Ms in the FeSiB/Ni layer. When the number of FeSiB foils is four, the maximum remanent aME,b and aME,I at zero bias magnetic field are 57.8 V/cm·Oe and 107.6 V/cm·Oe, respectively. It is recommended that the high-permeability alloy is supposed to have larger λs and μ0Ms for obtaining a larger remanent self-biased ME responses in ME composite with high-permeability alloy.     

Ionization Potentials and Quantum Defects of ls^2np^2p Rydberg States of Lithium Atom

Abstract In this work, ionization potentials and quantum effects of ls^2 np^2 P Rydberg states of lithium are calculated based on the calibrated quantum defect function. Energy levels and quantum defects for ls^2np^2P bound states and their adjacent continuum states are calculated with the R-matrix theory, and then the quantum defect function of the ls^2np （n ≥ 7） channel is obtained, which varies smoothly with the energy based on the quantum defect theory. The accurate quantum defect of the ls^2 7p^2P state derived from the experimental data is used to calibrate the original quantum defect function. The new function is used to calculate ionization potentials and quantum effects of ls^2np ^2P （n ≥ 7） Rydberg states. Present calculations are in agreement with recent experimental data in whole.     

Ferromagnetism in one-dimensional Hubbard model induced by the next-nearest-neighbor hopping at electron density 3/2

Ferromagnetism in the one-dimensional Hubbard model with the next-nearest-neighbor hopping is explored by using the exact-diagonalization method in a small cluster and the equation-of-motion method in the thermodynamic limit with electron density n = 3/2. With these two complementary methods, it is found that an intermediate value of the next-nearest- neighbor hopping amplitude tl tends to stabilize the fully polarized ferromagnetic state under the condition that the on-site coulomb interaction U is sufficiently large in our model. The ground-state phase diagram of the model is presented in the tl-U plane.     

Transport properties and anomalous fatigue effect of Ag/Bi0.9La0.lFeO3/La0.7Sr0.3MnO3 heterostructures

The transport properties and fatigue effect of Ag/Bi0.9La0.lFeO3/La0.7Sr0.3MnO3 heterostructures are described. By examining the I-V curves, an anomalous fatigue effect was found and its influences on resistive states were studied. I-V curves combined with C-f spectra were used to directly analyze the transport properties and fatigue effect. Compared to the first I-V cycle state, this structure shows more than one order increase of resistance after 100 cycles of ＂I-V curve training＂. The redistribution of oxygen vacancies in the depletion layer of Ag/Bi0.9La0.lFeO3 is believed to be responsible for the different resistance mechanisms and tenfold magnitude drop in resistance. The resistive switching is understood to be caused by electric field-induced carrier trapping and detrapping, which changes the depletion layer thickness at the Ag/Bi0.9La0.lFeO3 interface.     

Stereodynamics of the reactions Ne＋H＋/Ne＋D2＋/Ne＋W2

The vector correlations between products and reagents for the reactions Ne＋H2＋, Ne＋D2＋, and Ne＋T2＋ are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lfi et al, [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections （27π/σ）（dσ00/dωt）, （2π/σ）（dσ20/dwt）, （27π/σ）（dσ22＋/dwt）, and （2π/σ）（dσ21-/dwt）, and the distributions of P（θr）, P（φ）, and P（θr, Cr） are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed.     

Performance of a double sided silicon strip detector as a transmission detector for heavy ions

The performance of a double sided silicon strip detector （DSSSD）, which is used for the position and energy detection of heavy ions, is reported. The analysis shows that although the incomplete charge collection （ICC） and charge sharing （CS） effects of the DSSSD give rise to a loss of energy resolution, the position information is recorded without ambiguity. Representations of ICC/CS events in the energy spectra are shown and their origins are confirmed by correlation analysis of the spectra from both the junction side and ohmic side of the DSSSD.