Effective dynamics for a spin-1/2 particle constrained to a curved layer with inhomogeneous thickness

We derive an effective Hamiltonian for a spin-1/2 particle confined within a curved thin layer with non-uniform thickness using the confining potential approach.Our analysis reveals the presence of a pseudo-magnetic field and effective spin–orbit interaction(SOI)arising from the curvature,as well as an effective scalar potential resulting from variations in thickness.Importantly,we demonstrate that the physical effect of additional SOI from thickness fluctuations vanishes in low-dimensional systems,thus guaranteeing the robustness of spin interference measurements to thickness imperfection.Furthermore,we establish the applicability of the effective Hamiltonian in both symmetric and asymmetric confinement scenarios,which is crucial for its utilization in one-side etching systems.

Nonlinear modes coupling of trapped spin-orbit coupled spin-1 Bose-Einstein condensates

We study analytically and numerically the nonlinear collective dynamics of quasi-one-dimensional spin-orbit coupled spin-1 Bose-Einstein condensates trapped in harmonic potential.The ground state of the system is determined by minimizing the Lagrange density,and the coupled equations of motions for the center-of-mass coordinate of the condensate and its width are derived.Then,two low energy excitation modes in breathing dynamics and dipole dynamics are obtained analytically,and the mechanism of exciting the anharmonic collective dynamics is revealed explicitly.The coupling among spin-orbit coupling,Raman coupling and spin-dependent interaction results in multiple external collective modes,which leads to the anharmonic collective dynamics.The cooperative effect of spin momentum locking and spin-dependent interaction results in coupling of dipolar and breathing dynamics,which strongly depends on spin-dependent interaction and behaves distinct characters in different phases.Interestingly,in the absence of spin-dependent interaction,the breathing dynamics is decoupled from spin dynamics and the breathing dynamics is harmonic.Our results provide theoretical evidence for deep understanding of the ground sate phase transition and the nonlinear collective dynamics of the system.

Spin-1 Blume-Capel model with longitudinal random crystal and transverse magnetic fields:A mean-field approach

The spin-1 Blume–Capel model with transverse and longitudinal external magnetic fields h, in addition to a longitudinal random crystal field D, is studied in the mean-field approximation. It is assumed that the crystal field is either turned on with probability p or turned off with probability 1 p on the sites of a square lattice. Phase diagrams are then calculated on the reduced temperature crystal field planes for given values of γ=Ω/J and p at zero h. Thus, the effect of changing γ and p are illustrated on the phase diagrams in great detail and interesting results are observed.

Gapped Spin-1/2 Spinon Excitations in a New Kagome Quantum Spin Liquid Compound Cu_3Zn(OH)_6FBr

We report a new kagome quantum spin liquid candidate CuaZn（OH）6FBr, which does not experience any phase transition down to 50inK, more than three orders lower than the antiferromagnetic Curie-Weiss temperature （-200 K）. A clear gap opening at low temperature is observed in the uniform spin susceptibility obtained from 19F nuclear magnetic resonance measurements. We observe the characteristic magnetic field dependence of the gap as expected for fractionalized spin-1/2 spinon excitations. Our experimental results provide firm evidence for spin fractionalization in a topologically ordered spin system, resembling charge fraetionalization in the fractional quantum Hall state.

Discovery of Fractionalized Neutral Spin-1/2 Excitation of Topological Order

After the discovery of fraction quantum Hall states in the 1980s, it became more and more clear that Landau symmetry breaking theory does not describe all possible quantum phases of matter. The new quan- tum phases of matter were called topologically ordered phases（for gapped cases） or quantum ordered phases （for gapless cases）, which correspond to pat- terns of many-body entanglement. One may won- der： besides quantum Hall systems, are there other systems that realize the new topological/quantum order？

Thermal entanglement in two-qutrit spin-1 anisotropic Heisenberg model with inhomogeneous magnetic field

The thermal entanglement of a two-qutrit spin-1 anisotropic Heisenberg XXZ chain in an inhomogeneous magnetic field is studied in detail. The effects of the external magnetic field （B）, a parameter b which controls the inhomogeneity of B, and the bilinear interaction parameters Jx = Jy ≠ Jz on the thermal variation of the negativity are studied in detail. It is found that negativity N decreases when the values of magnetic field, inhomogeneity b and temperature are increasing. In addition, N remains at higher temperatures for higher values of Jz and lower values of B and b.

Soliton breathers in spin-1 Bose–Einstein condensates

We consider a spin-1 Bose-Einstein condensate trapped in a harmonic potential with different nonlinearity coeffi- cients. We illustrate the dynamics of soliton breathers in two-component and three-component states by numerically solv- ing the one-dimensional time-dependent coupled Gross-Pitaecskii equations （GPEs）. We present that two condensates with repulsive interspecies interactions make elastic collision and novel soliton breathers are created in two-component state. We also demonstrate novel soliton breathers in three-component state with attractive coupling constants. Furthermore, possible reasons for creating soliton breathers are discussed.

LnCu_(3)(OH)_(6)Cl_(3) (Ln=Gd, Tb, Dy): Heavy lanthanides on spin-1/2 kagome magnets

The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by the hydrothermal method.LnCu_(3)(OH)_(6)Cl_(3) adopts space group P3m1 and features the layered Cu-kagome lattice with lanthanide Ln3+cations sitting at the center of the hexagons.Although heavy lanthanides(Ln=Gd,Tb,Dy)in LnCu_(3)(OH)_(6)Cl_(3) provide a large effective magnetic moment and ferromagnetic-like spin correlations compared to light-lanthanides(Nd,Sm,Eu)analogues,Cu-kagome holds an antiferromagnetically ordered state at around 17 K like YCu_(3)(OH)_(6)Cl_(3).

The Mixed Spin-1/2 and Spin-1 Ising–Heisenberg Model in the Mean-Field Approximation: a New Approach

Thermodynamic properties of the mixed spin-1 and spin-1/2 Ising-Heisenberg model are studied on a honeycomb lattice using a new approach in the mean-field approximation to analyze the effects of longitudinal Dz and transverse Dx crystal fields. The phase diagrams are calculated in detail by studying the thermal variations of the order parameters, i.e., magnetizations and quadrupole moments, and compared with the literature to assess the reliability of the new approach. It is found that the model yields both second- and first-order phase transitions, and tricritical points. The compensation behavior of the model is also investigated for the sublattice magnetizations, and longitudinal and transverse quadrupolar moments. The latter type of compensation is observed in the literature but its possible importance is overlooked.

Weak Nonlinear Matter Waves in a Trapped Spin-1 Condensates

The dynamics of the weak non//near matter sofitary waves in a spin-1 condensates with harmonic external potential are investigated analytically by a perturbation method. It is shown that, in the small amplitude limit, the dynamics of the solitary waves are governed by a variable-coetficient Korteweg-de Vries （KdV） equation. The reduction to the （KdV） equation may be useful to understand the dynamics of nonlinear matter waves in spinor BECs. The analytical expressions for the evolution of soliton show that the small-amplitude vector solitons of the mixed types perform harmonic oscillations in the presence of the trap. Furthermore, the emitted radiation profiles and the soliton oscillation frequency are also obtained.

Energy Levels of Spin-1/2 Particles with Yukawa Interaction

In this article, Yukawa interaction is used to study the relativistic spin-1/2 particles and obtain their energy levels. The role of Yukawa potential on the spin and pseudospin symmetry solution is investigated systematically by solving the Dirac equation with attractive scalar S(r) and repulsive vector V(r) potentials. Bound state spectrum and wave functions of Yukawa potential are obtained. It is found that the energy eigenvalues strongly depend on the potential parameters.

Cavity-enhanced metrology in an atomic spin-1 Bose−Einstein condensate

Atom interferometer has been proven to be a powerful tool for precision metrology. Here we propose a cavity-aided nonlinear atom interferometer, based on the quasi-periodic spin mixing dynamics of an atomic spin-1 Bose−Einstein condensate trapped in an optical cavity. We unravel that the phase sensitivity can be greatly enhanced with the cavity-mediated nonlinear interaction. The influence of encoding phase, splitting time and recombining time on phase sensitivity are carefully studied. In addition, we demonstrate a dynamical phase transition in the system. Around the criticality, a small cavity light field variation can arouse a strong response of the atomic condensate, which can serve as a new resource for enhanced sensing. This work provides a robust protocol for cavity-enhanced metrology.

考虑源荷不确定性和N-1安全约束的电力系统优化调度

大规模风电并网增加了系统运行的不确定因素,文章利用快速可调资源平抑风电和负荷波动引发的功率不平衡,并考虑备用调用过程减少对系统潮流的影响。首先分析了风电和负荷预测误差的概率分布模型;然后,建立含N-1网络安全机会约束和旋转备用机会约束的电力系统优化调度模型,以系统调度总成本最小为目标优化机组出力;最后,基于起作用整数变量的识别方法的Benders分解法处理N-1网络安全约束,提高求解效率。利用修正的IEEE30节点系统,验证了所提模型能够保障系统备用可用性、经济性和安全性,充分挖掘抽水蓄能的快速可调能力。

Analytical solutions for the spin-1 Bose-Einstein condensate in a harmonic trap

The homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions for the Gross-Pitaevskii equations, a set of nonlinear SchrSdinger equation used in simulation of spin-1 Bose-Einstein condensates trapped in a harmonic potential. We investigate the one-dimensional case and get the approximate analytical solutions successfully. Comparisons between the analytical solutions and the numerical solutions have been made. The results indicate that they are in agreement well with each other when the atomic interaction is weakly. We also find a class of exact solutions for the stationary states of the spin-1 system with harmonic potential for a special case.

Topological excitations in rotating spin-orbit-coupled spin-1 Bose-Einstein condensates with in-plane gradient magnetic field

We investigate the topological excitations of rotating spin-1 ferromagnetic Bose–Einstein condensates with spin–orbit coupling(SOC)in an in-plane quadrupole field.Such a system sustains a rich variety of exotic vortex structures due to the spinor order parameter and the interplay among in-plane quadrupole field,SOC,rotation,and interatomic interaction.For the nonrotating case,with the increase of the quadrupole field strength,the system experiences a transition from a coreless polar-core vortex with a bright soliton to a singular polar-core vortex with a density hole.Without rotation but with a fixed quadrupole field,when the SOC strength increases,the system transforms from a central Mermin–Ho vortex into a criss-crossed vortex–antivortex string lattice.For the rotating case,we give a phase diagram with respect to the quadrupole field strength and the SOC strength.It is shown that the rotating system supports four typical quantum phases:vortex necklace,diagonal vortex chain cluster,single diagonal vortex chain,and few vortex states.Furthermore,the system favors novel spin textures and skyrmion excitations including an antiskyrmion,a criss-crossed half-skyrmion–half-antiskyrmion lattice,a skyrmion-meron necklace,a symmetric half-skyrmion lattice,and an asymmetric skyrmionmeron lattice.

Acoustic spin-1 Weyl semimetal

The study of topological semimetals hosting spin-1 Weyl points(WPs)beyond Dirac points and WPs has attracted a great deal of attention.However,a spin-1 Weyl semimetal that exclusively possesses spin-1 WPs in a clean frequency window without being shadowed by any other nodal points is yet to be discovered.This study reports a spin-1 Weyl semimetal in a phononic crystal.Its spin-1 WPs are touched by two linear dispersions and an additional flat band and carry monopole charges(-2,0,2)or(2,0,-2)for the three bands from the bottom to the top.They result in double Fermi arcs,which occur between the first and second bands,as well as between the second and third bands.Further robust propagation is observed against the multiple joints and topological negative refraction of the acoustic surface arc wave.The results of this study create the basis for the exploration of the unusual properties of spin-1 Weyl physics on a macroscopic scale.

CP-Violation from Spin-1 Resonances in a Left-Right Dynamical Higgs Context

New physics field content in the nature, more specifically, from spin-1 resonances sourced by the extension of the SM local gauge symmetry to the larger local group SU(2)_LSU(2)_R U(1)_(B-L), may induce CP-violation signalling NP effects from higher energy regimes. In this work we completely list and study all the CP-violating operators up to the p^4-order in the Lagrangian expansion, for a non-linear left-right electroweak chiral context and coupled to a light dynamical Higgs. Heavy right handed fields can be integrated out from the physical spectrum, inducing thus a physical impact in the effective gauge couplings, fermionic electric dipole moment, and CP-violation in the decay h→ ZZ*→4 l that are briefly analysed. The final relevant set of effective operators have also been identified at low energies.

动脉自旋标记和扩散张量成像评估脑胶质瘤IDH1基因表型的价值研究

目的 探讨常规MRI联合动脉自旋标记(arterial spin labeling,ASL)成像、扩散张量成像(diffusion tensor imaging,DTI)在评估胶质瘤异柠檬酸脱氢酶1(isocitrate dehydrogenase 1,IDH1)表型中的价值。材料与方法 回顾性分析2019年9月至2021年12月经病理证实为胶质瘤患者病例61例,根据基因或免疫组化检测IDH1表型,分为IDH1突变型(IDH1_(mutant),IDH1_(mut))组和IDH1野生型(IDH1 wild,IDH1_(wt))组,术前行颅脑MRI常规检查及ASL、DTI检查。评估IDH1_(mut)、IDH1_(wt)胶质瘤常规MRI特征(大小、位置、边缘、坏死囊变、出血、水肿和强化),测量肿瘤实性区、瘤周区的各向异性分数(anisotropy fraction,FA)、表观扩散系数(apparent diffusion coefficient,ADC)、脑血流量最大值(_(max)imum cerebral blood flow,CBF_(max))、平均值(_(mean) cerebral blood flow,CBF_(mean)),计算相对脑血流量最大值(relativer CBF_(max),r CBF_(max))、相对脑血流量平均值(relativer CBF_(mean),r CBF_(mean))。采用SPSS 25.0进行统计学分析。所有样本组间分析采用独立样本t检验或非参数检验进行分析,建立多因素logistic回归模型并绘制受试者工作特征(receiver operating characteristic,ROC)曲线预测其诊断效能。结果 本研究共纳入胶质瘤患者病例61例:IDH_(mut)19例、IDH1_(wt)42例。IDH1_(mut)与IDHwt胶质瘤的位置、强化、水肿、肿瘤实性区CBF、瘤周区ADC具有显著性差异(P<0.05);IDH1_(wt)肿瘤实性区CBF_(max)、CBF_(mean)、r CBF_(max)、r CBF_(mean)高于IDH1_(mut)型(P<0.05),曲线下面积(area under the curve,AUC)分别为0.879、0.832、0.806、0.875;IDH1_(wt)瘤周ADC值高于IDH1_(mut)(P<0.05)。肿瘤实质区CBF_(mean)联合瘤周ADC诊断IDH1表型的效能最高(AUC=0.892)。多因素logistic回归显示肿瘤实体区CBF是胶质瘤IDH1表型预测的独立风险因素。结论 常规MRI特征、ASL及DTI对胶质瘤IDH1表型评估具有重要临床价值,联合肿瘤实质区CBF、瘤周ADC值可进一步提高胶质瘤IDH1表型的诊断效能。

Hexagonal Type Ising Nanowire with Spin-1 Core and Spin-2 Shell Structure

Thermodynamic properties and phase diagrams of a mixed spin-(1,2) Ising ferrimagnetic system with single ion anisotropy on hexagonal nanowire are studied by using effective-field theory with correlations. The susceptibility,internal energy and specific heat of the system are numerically examined and some interesting phenomena in these quantities are found. The effect of the Hamiltonian parameters on phase diagrams are examined in detail. Besides second-order phase transition, lines of first-order transition and tricritical points are found. In particular, we found that for some negative values of single-ion anisotropies, there exist first-order phase transitions.

Experimental simulation of spin-1 states by second-order type-Ⅱ parametric down-conversion

In this paper,by using the second-order parametric down-conversion of the nonlinear crystal,the spin-1 state is simulated by the two-photon polarization entangled modes. Through adjusting the laser pulse power density,the efficiency of second-order parametric down-conversion is enhanced. The intensity of the spin-1 state is 0.5/s. The fidelity of the state is up to F=0.891±0.002,and the contrast is C=17.3. The results provide a new method for Stern-Gerlach measurement on the spin-1 system.