检索结果-南通市图书馆

Discovery of controllable high Chern number quantum anomalous Hall state in tetragonal lattice FeSIn

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第6期33卷 504-509页

作者：任小浪张昌文 school of physics and Technology Institute of SpintronicsUniversity of JinanJinan 250022China

Quantum anomalous Hall(QAH) insulators have excellent properties driven by fancy topological physics, but their practical application is greatly hindered by the observed temperature of liquid nitrogen, and the QAH insulator with high Chern number is conducive to spintronic devices with lower energy consumption. Here, we find that monolayer Fe SIn is a good candidate for realizing the QAH phase;it exhibits a high magnetic transition temperature of 221 K and tunable C = ±2 with respect to magnetization orientation in the y–z plane. After the application of biaxial strain, the magnetic axis shifts from the x–y plane to the z direction, and the effect of the high C and ferromagnetic ground state on the stress is robust. Also, the effect of correlation U on C has been examined. These properties are rooted in the large size of the Fe atom that contributes to ferromagnetic kinetic exchange with neighboring Fe atoms. These findings demonstrate monolayer Fe SIn to be a major template for probing novel QAH devices at higher temperatures.

关键词： high Chern number Weyl semimetals quantum anomalous Hall insulator magnetic transition temperature

Mechanical and magnetocaloric adjustable properties of Fe3O4/PET deformed nanoparticle film

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第3期33卷 589-595页

作者：范凤国段林彤 school of physics and Electrical Information Shangqiu Normal UniversityShangqiu 476000China

The flexibility of nanoparticle films is a topic of rapidly growing interest in both scientific and engineering researches due to their numerous potential applications in a broad range of wearable electronics and biomedical *** article presents the elucidation of the properties of nanoparticle ***,a flexible film is fabricated based on polyethylene terephthalate(PET)and magnetic iron oxide at the nanoscale using layer-by-layer *** 2D thin flexible film material can be bent at different angles from 0°to 360°.With an increase in elastic deformation angles,the magnetocaloric effect of the film gradually increases in the alternating magnetic *** test results from a vibrating sample magnetometer and a low-frequency impedance analyzer demonstrate that the film has a good magnetic response and *** magnetocaloric effect and magnetic induction effect are controlled by deformation,providing a new idea for the application of elastic *** combines the flexibility of the nanoparticle PET substrate and,in the future,it may be used for skin adhesion for administration and magnetic stimulation control.

关键词： nanoparticle film deformation magnetic properties flexible substrates

High-visibility ghost imaging with phase-controlled discrete classical light sources

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第7期33卷 328-334页

作者：仵雪滢赵岳李利明 school of physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255049China

We take phase modulation to create discrete phase-controlled sources and realize the super-bunching effect by a phasecorrelated method. From theoretical and numerical simulations, we find the space translation invariance of the bunching effect is a key point for the ghost imaging realization. Experimentally, we create the orderly phase-correlated discrete sources which can realize high-visibility second-order ghost imaging than the result with chaotic sources. Moreover, some factors affecting the visibility of ghost image are discussed in detail.

关键词： ghost imaging high visibility space translation invariance

An approximate Kerr–Newman-like metric endowed with a magnetic dipole and mass quadrupole

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第8期76卷 126-140页

作者： Francisco Frutos-Alfaro Space Research Center and school of physics University of Costa Rica

Approximate all-terrain spacetimes for astrophysical applications are presented. The metrics possess five relativistic multipole moments, namely, mass, rotation, mass quadrupole, charge,and magnetic dipole moment. All these spacetimes approximately satisfy the Einstein–Maxwell field equations. The first metric is generated using the Hoenselaers–Perjés method from given relativistic multipoles. The second metric is a perturbation of the Kerr–Newman metric, which makes it a relevant approximation for astrophysical calculations. The last metric is an extension of the Hartle–Thorne metric that is important for obtaining internal models of compact objects perturbatively. The electromagnetic field is calculated using Cartan forms for locally non-rotating observers. These spacetimes are relevant for inferring properties of compact objects from astrophysical observations. Furthermore, the numerical implementations of these metrics are straightforward, making them versatile for simulating potential astrophysical applications.

关键词： Compact objects Einstein-Maxwell equations Gravitation

Bubble nucleation in the two-flavor quark-meson model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese physics C 2024年第5期48卷 92-106页

作者：汪俊荣余紫琬毛鸿 school of physics Hangzhou Normal UniversityHangzhou 311121China

We investigate the dynamics of a first-order quark-hadron transition via homogeneous thermal nucleation in the two-flavor quark-meson *** contribution of the fermionic vacuum loop in the effective thermodynamics potential and phase diagram,together with the location of the critical endpoint(CEP),is obtained in the temperature and chemical potential *** weak and strong first-order phase transitions,by taking the temperature as a variable,the critical bubble profiles,evolutions of the surface tension,and saddle-point action in the presence of a nucleation bubble are numerically calculated in detail when fixing the chemical potentials atμ=306 MeV andμ=309 *** results show that the system could be trapped in the metastable state for a long time as long as the temperature is between the metastable region characterized by the up and low spinodal ***,the surface tension at criticality will rise to approximately 4 MeV/fm2 when the chemical potential is very *** a small surface tension value would favor a mixed phase in the cores of compact stars and may have an important implication in astrophysics.

关键词： quark-meson model nucleation false vacuum decay surface tension first-order phase transition

Coexistence of antiferromagnetism and unconventional superconductivity in a quasi-one-dimensional flat-band system:Creutz lattice

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第3期33卷 583-588页

作者：徐峰张磊 school of physics and Telecommunication Engineering Shaanxi University of TechnologyHanzhong 723001China

We study the coexistence of antiferromagnetism and unconventional superconductivity on the Creutz lattice which shows strictly flat bands in the noninteracting *** famous renormalized mean-field theory is used to deal with strong electron-electron repulsive Hubbard interaction in the effective low-energy t-J model,the superfluid weight of the unconventional superconducting state has been calculated via the linear response *** unconventional superconducting state with both spin-singlet and staggered spin-triplet pairs emerges beyond a critical antiferromagnetic coupling interaction,while antiferromagnetism accompanies this *** superconducting state with only spin-singlet pairs is dominant with paramagnetic *** A phase is analogous to the pseudogap phase,which shows that electrons go to form pairs but do not cause a *** also show the superfluid behavior of the unconventional superconducting state and its critical *** is proven directly that the flat band can effectively raise the critical temperature of *** is implementable to simulate and control strongly-correlated electrons'behavior on the Creutz lattice in the ultracold atoms experiment or other artificial *** results may help the understanding of the interplay between unconventional superconductivity and magnetism.

关键词： flat-band unconventional superconductivity antiferromagnetism strong electron-electron interaction superfluid weight

A global model of intensity autocorrelation to determine laser pulse duration

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第5期33卷 446-451页

作者：彭雨菲刘励强洪丽红李志远 school of physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

We present a new global model of collinear autocorrelation based on second harmonic generation *** model is rigorously derived from the nonlinear coupled wave equation specific to the autocorrelation measurement configuration,without requiring a specific form of the incident pulse function.A rigorous solution of the nonlinear coupled wave equation is obtained in the time domain and expressed in a general analytical *** global model fully accounts for the nonlinear interaction and propagation effects within nonlinear crystals,which are not captured by the classical local *** assess the performance of the global model compared to the classic local model,we investigate the autocorrelation signals obtained from both models for different incident pulse waveforms and different full-widthes at half-maximum(FWHMs).When the incident pulse waveform is Lorentzian with an FWHM of 200 fs,the global model predicts an autocorrelation signal FWHM of 399.9 fs,while the classic local model predicts an FWHM of 331.4 *** difference between the two models is 68.6 fs,corresponding to an error of 17.2%.Similarly,for a sech-type incident pulse with an FWHM of 200 fs,the global model predicts an autocorrelation signal FWHM of 343.9 fs,while the local model predicts an FWHM of 308.8 *** difference between the two models is 35.1 fs,with an error of 10.2%.We further examine the behavior of the models for Lorentzian pulses with FWHMs of 100 fs,200 fs and 500 *** differences between the global and local models are 17.1 fs,68.6 fs and 86.0 fs,respectively,with errors approximately around 17%.These comparative analyses clearly demonstrate the superior accuracy of the global model in intensity autocorrelation modeling.

关键词： intensity autocorrelation global model ultrashort pulses pulse-width measurement

Phonon resonance modulation in weak van der Waals heterostructures:Controlling thermal transport in graphene-silicon nanoparticle systems

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第4期33卷 96-102页

作者：李毅刘一浓胡世谦 school of physics and Astronomy Yunnan UniversityKunming 650091China

The drive for efficient thermal management has intensified with the miniaturization of electronic *** study explores the modulation of phonon transport within graphene by introducing silicon nanoparticles influenced by van der Waals *** approach involves the application of non-equilibrium molecular dynamics to assess thermal conductivity while varying the interaction strength,leading to a noteworthy reduction in thermal ***,we observe a distinct attenuation in length-dependent behavior within the graphene-nanoparticles *** exploration combines wave packet simulations with phonon transmission calculations,aligning with a comprehensive analysis of the phonon transport regime to unveil the underlying physical mechanisms at ***,we conduct transient molecular dynamics simulations to investigate interfacial thermal conductance between the nanoparticles and the graphene,revealing an enhanced thermal boundary *** research not only contributes to our understanding of phonon transport but also opens a new degree of freedom for utilizing van der Waals nanoparticle-induced resonance,offering promising avenues for the modulation of thermal properties in advanced materials and enhancing their performance in various technological applications.

关键词： thermal conductivity molecular dynamics phonon resonance van der Waals interaction graphene-silicon nanoparticle heterostructure

Electronic property and topological phase transition in a graphene/CoBr_(2) heterostructure

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第2期33卷 498-505页

作者：秦元秀李胜世纪维霄张昌文 school of physics and Technology Institute of SpintronicsUniversity of JinanJinan 250022China

Recently,significant experimental advancements in achieving topological phases have been reported in van der Waals(vdW)heterostructures involving ***,using first-principles calculations,we investigate graphene/CoBr_(2)(Gr/CoBr_(2))heterostructures and find that an enhancement of in-plane magnetic anisotropy(IMA)energy in monolayer CoBr_(2) can be accomplished by reducing the interlayer distance of the vdW *** addition,we clarify that the enhancement of IMA energy primarily results from two factors:one is the weakness of the Co-d_(xy) and Co-d_(x^(2)-y^(2)) orbital hybridization and the other is the augmentation of the Co-d_(yz) and Co-d_(z)2 orbital ***,calculation results suggest that the Kosterlitz–Thouless phase transition temperature(TKT)of a 2D XY magnet Gr/CoBr_(2)(23.8 K)is higher than that of a 2D XY monolayer CoBr_(2)(1.35 K).By decreasing the interlayer distances,the proximity effect is more pronounced and band splitting ***,by taking into account spin–orbit coupling,a band gap of approximately 14.3 meV and the quantum anomalous Hall effect(QAHE)are attained by decreasing the interlayer distance by 1.0 *** by the above conclusions,we design a topological field transistor device *** results support that the vdW interlayer distance can be used to modulate the IMA energy and QAHE of materials,providing a pathway for the development of new low-power spintronic devices.

关键词： van der Waals heterostructure in-plane magnetic anisotropy energy quantum anomalous Hall effect