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Cosmological constraints on neutrino mass within consistent cosmological models

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Chinese Physics C 2024年第6期48卷 191-197页

作者：庞业煌张雪黄庆国 School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China School of physical Sciences University of Chinese Academy of SciencesBeijing 100049China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

Recently,the emergence of cosmological tension has raised doubts about the consistency of the ACDM *** constrain the neutrino mass within a consistent cosmological framework,we investigate three massive neutrinos with normal hierarchy(NH)and inverted hierarchy(IH)in both the axion-like early dark energy(AxiEDE)and AdS-EDE *** use joint datasets including the cosmic microwave background power spectrum from Plaanck 2018,Pantheon of type la supernova,baryon acoustic oscillation,and H0data from *** the vAxi-EDE model,we obtain∑m_(v),NH<0.152 eV and∑m_(v),IH<0.178 eV,whereas for the vAdS-EDE model,we find∑m_(v),NH<0.135 eV and∑m_(v),IH<0.167 *** results exhibit a preference for NH in both the vAxi-EDE and vAdS-EDE models.

关键词： neutrino mass cosmological tension early dark energy

Quasinormal modes and ringdown waveforms of a Frolov black hole

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Communications in Theoretical Physics 2024年第10期76卷 101-107页

作者： Zhijun Song Huajie Gong Hai-Li Li Guoyang Fu Li-Gang Zhu Jian-Pin Wu Center for Gravitation and Cosmology College of Physical Science and Technology Yangzhou University Basic Teaching Department Shenyang Institute of Engineering Department of Physics and Astronomy Shanghai Jiao Tong University

In this paper we investigate scalar perturbation over a Frolov black hole（BH）, which is a regular BH induced by the quantum gravity effect. The quasinormal frequencies of a scalar field always consistently reside in the lower half-plane, and the time-domain evolution of the field demonstrates a decaying behavior, with the late-time tail exhibiting a power-law pattern. These observations collectively suggest the stability of a Frolov BH against scalar ***, our study reveals that the quantum gravity effect leads to slower decay modes. For the case of the angular quantum number l = 0, the oscillation exhibits non-monotonic behavior with the quantum gravity parameter α0. However, once l ≥ 1, the angular quantum number surpasses the influence of the quantum gravity effect.

关键词： black hole Frolov black hole quantum gravity effects quasinormal modes

Improving the electrical performances of InSe transistors by interface engineering

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Chinese Physics B 2024年第4期33卷 153-158页

作者：曹天俊郝松吴晨晨潘晨戴玉頔程斌梁世军缪峰 institute of Brain-Inspired Intelligence National Laboratory of Solid State MicrostructuresSchool of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China institute of Interdisciplinary physical Sciences School of PhysicsNanjing University of Science and TechnologyNanjing 210014China

InSe has emerged as a promising candidate for next-generation electronics due to its predicted ultrahigh electrical ***,the efficacy of the InSe transistor in meeting application requirements is hindered due to its sensitivity to *** this study,we have achieved notable enhancement in the electrical performance of InSe transistors through interface *** engineered an InSe/h-BN heterostructure,effectively suppressing dielectric layer-induced ***,we successfully established excellent metal-semiconductor contacts using graphene ribbons as a buffer *** a methodical approach to interface engineering,our graphene/InSe/h-BN transistor demonstrates impressive on-state current,field-effect mobility,and on/off ratio at room temperature,reaching values as high as 1.1 mA/μm,904 cm^(2)·V^(-1)·s^(-1),and>10~6,*** computations corroborate that the graphene/InSe heterostructure shows significant interlayer charge transfer and weak interlayer interaction,contributing to the enhanced performance of InSe *** research offers a comprehensive strategy to elevate the electrical performance of InSe transistors,paving the way for their utilization in future electronic applications.

关键词： two-dimensional materials InSe van der Waals heterostructure electrical performances charge density difference

Experimental results of a magnetic field modification to the radio frequency driver of a negative ion source

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Plasma Science and Technology 2024年第4期26卷 162-167页

作者：谢俊炜谢亚红韦江龙梁立振彭旭峰杨宇雯顾玉明胡纯栋谢远来 institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031People’s Republic of China University of Science and Technology of China Hefei 230026People’s Republic of China

A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in front of the PG. However, the magnetic field diffused into the driver has some influence on the plasma outflowing. In order to investigate the effect of changing this magnetic field on the outflowing of plasma from the driver, a circular ring(absorber) of high permeability iron has been introduced at the driver exit, which can reduce the magnetic field around it and improve plasma outflowing. With the application of the absorber, the electron density is increased by about 35%, and the extraction current measured from the extraction grid is increased from 1.02 A to 1.29 A. The results of the extraction experiment with cesium injection show that both the extraction grid(EG) current and H-current are increased when the absorber is introduced.

关键词： neutral beam injection negative ion source magnetic filter radio frequency ion source

Magnetism of NaYbS_(2):From finite temperatures to ground state

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 92-104页

作者： Weizhen Zhuo Zheng Zhang Mingtai Xie Anmin Zhang Jianting Ji Feng Jin Qingming Zhang School of physical Science and Technology Lanzhou UniversityLanzhou 730000China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Rare-earth chalcogenide compounds ARECh_(2)(A=alkali or monovalent metal,RE=rare earth,Ch=O,S,Se,Te)are a large family of quantum spin liquid(QSL)candidate ***2is a representative member of the *** key issues on NaYbS_(2),particularly how to determine the highly anisotropic spin Hamiltonian and describe the magnetism at finite temperatures and the ground state,remain to be *** this paper,we conducted an in-depth and comprehensive study on the magnetism of NaYbS_(2) from finite temperatures to the ground ***,we successfully detected three crystalline electric field(CEF)excitation energy levels using low-temperature Raman scattering *** them with the CEF theory and magnetization data,we worked out the CEF parameters,CEF energy levels,and CEF *** further determined a characteristic temperature of~40 K,above which the magnetism is dominated by CEF excitations while below which the spinexchange interactions play a main *** characteristic temperature has been confirmed by the temperature-dependent electron spin resonance(ESR)***-temperature ESR experiments on the dilute magnetic doped crystal of NaYb_(0.1)Lu_(0.9)S_(2) further helped us to determine the accurate ***,we quantitatively obtained the spin-exchange interactions in the spin Hamiltonian by consistently simulating the magnetization and specific heat ***,the above studies allow us to explore the ground state magnetism of NaYbS_(2) by using the density matrix renormalization *** combined numerical calculations and experimental results to demonstrate that the ground state of NaYbS_(2) is a Dirac-like QSL.

关键词： rare-earth chalcogenide anisotropic spin Hamiltonian quantum spin liquid

Conceptual design of the tail research experiment at the Space Plasma Environment Research Facility(SPERF-TREX)

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Plasma Science and Technology 2024年第8期26卷 44-49页

作者：肖青梅毛傲华何向磊邹继同杨肖易孙萌萌李丰汤鹏飞周田春王晓钢 the SPERF Team Laboratory for Space Environment and physical Sciences Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of Physics Harbin Institute of TechnologyHarbin 150001People’s Republic of China Heilongjiang Provincial Key Laboratory of Plasma Physics and Application Technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China

The Space Plasma Environment Research Facility(SPERF)for ground simulation of the space plasma environment is a key component of the Space Environment Simulation Research Infrastructure(SESRI),a major national science and technology infrastructure for fundamental *** is designed to investigate outstanding issues in the space plasma environment,such as energetic particle acceleration,transport,and interaction with electromagnetic waves,as well as magnetic reconnection processes,in magnetospheric *** Tail-Research EXperiment(TREX)is part of the SPERF for laboratory studies of space physics relevant to magnetic reconnection,dipolarization and hydromagnetic wave excitation in the *** is designed to carry out three types of experiments:the tail plasmoid for magnetic reconnection,dipolarization front formation,and magnetohydrodynamic waves excited by highspeed plasma *** this paper,the scientific goals and three scenarios of SPERF-TREX for typical processes in space plasmas are presented,and experimental plans for SPERF-TREX are also reviewed,together with the plasma sources applied to generate the plasma with the desired parameters and various magnetic configurations.

关键词： SPERF-TREX wave-particle interaction magnetic reconnection dipolarization

Spin gap in quasi-one-dimensional S=3/2 antiferromagnet CoTi2O5

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Chinese Physics B 2024年第3期33卷 609-617页

作者：徐浩航刘庆元辛潮申沁鑫罗军周睿程金光刘健陶玲玲刘志国霍明学王先杰隋郁 School of Physics Harbin Institute of TechnologyHarbin 150001China School of Science Changchun University of Science and TechnologyChangchun 130022China Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China Laboratory for Space Environment and physical Sciences Harbin Institute of TechnologyHarbin 150001China Southwest institute of Applied Magnetics Mianyang 621000China

Quasi-one-dimensional(1D)antiferromagnets are known to display intriguing phenomena especially when there is a spin gap in their spin-excitation *** we demonstrate that a spin gap exists in the quasi-1D Heisenberg antiferromagnet CoTi2O5 with highly ordered Co2+/Ti4+occupation,in which the Co2+ions with S=3/2 form a 1D spin chain along the ***2O5 undergoes an antiferromagnetic transition at TN~24 K and exhibits obvious anisotropic magnetic susceptibility even in the paramagnetic *** a gapless magnetic ground state is usually expected in a quasi-1D Heisenberg antiferromagnet with half-integer spins,by analyzing the specific heat,the thermal conductivity,and the spin-lattice relaxation rate(1/T1)as a function of temperature,we found that a spin gap is opened in the spin-excitation spectrum of CoTi2O5 around TN,manifested by the rapid decrease of magnetic specific heat to zero,the double-peak characteristic in thermal conductivity,and the exponential decay of 1/T1 below *** the magnetic measurements and the first-principles calculations results indicate that there is spin-orbit coupling in CoTi2O5,which induces the magnetic anisotropy in CoTi2O5,and then opens the spin gap at low temperature.

关键词： quasi-one-dimensional antiferromagnet magnetic anisotropy spin gap

Numerical studies for plasmas of a linear plasma device HIT-PSI with geometry modified SOLPS-ITER

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Chinese Physics B 2024年第3期33卷 503-508页

作者：王敏聂秋月黄韬王晓钢张彦杰 School of Physics Harbin Institute of TechnologyHarbin 150001China School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001China Laboratory for Space Environment and physical Sciences Harbin Institute of TechnologyHarbin 150001China MOE (Ministry of Education) Key Laboratory of Materials Modification by Laser Ionand Electron BeamsSchool of PhysicsDalian Institute of TechnologyDalian 116024China

The HIT-PSI is a linear plasma device built for physically simulating the high heat flux environment of future reactor divertors to test/develop advanced target plate *** this study,the geometry-modified SOLPS-ITER program is employed to examine the effects of the magnetic field strength and neutral pressure in the device on the heat flux experienced by the target plate of the HIT-PSI *** findings of the numerical simulation indicate a positive correlation between the magnetic field strength and the heat flux ***,there is a negative correlation observed between the heat flux density and the neutral *** the magnetic field strength at the axis exceeds 1 tesla and the neutral pressure falls below 10 Pa,the HIT-PSI has the capability to attain a heat flux of 10 MW·m-2 at the target *** simulation results offer a valuable point of reference for subsequent experiments at HIT-PSI.

关键词： HIT-PSI heat flux linear plasma SOLPS-ITER device

Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

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Chinese Physics B 2024年第6期33卷 63-67页

作者：陈佳骏吕心邓李思敏但雅倩黄艳萍崔田 institute of High Pressure Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical ***,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical *** to 70 GPa,an unusual metal-semiconductor-metal transition *** first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti *** electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered *** pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase *** assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

关键词： high pressure transition metal dichalcogenides doped TiS_(2) electronic phase transition