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Journal of Applied Mathematics and Physics 2015年第12期3卷 1563-1570页

作者： Shen Li Clas Persson Department of Materials Science and Engineering Royal Institute of Technology Stockholm Sweden Department of Physics University of Oslo Oslo Norway

The narrow-gap semiconductor CsBi4Te6 is a promising material for low temperature thermoelectric applications. Its thermoelectric property is significantly better than the well-explored, high-performance thermoelectric material Bi2Te3 and related alloys. In this work, the thermal expansion and the heat capacity at constant pressure of CsBi4Te6 are determined within the quasiharmonic approximation within the density functional theory. Comparisons are made with available experimental data, as well as with calculated and measured data for Bi2Te3. The phonon band structures and the partial density of states are also investigated, and we find that both CsBi4Te6 and Bi2Te3 exhibit localized phonon states at low frequencies. At high temperatures, the decrease of the volume expansion with temperature indicates the potential of a good thermal conductivity in this temperature region.

关键词： Quasi Harmonic Approximation Thermal Expansion Heat Capacity phonon Dispersion

Robust and tunable Weyl phases by coherent infrared phonons in ZrTe_(5)

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npj Computational Materials 2022年第1期 1063-1071页

作者： Niraj Aryal Xilian Jin Qiang Li Mengkun Liu A.M.Tsvelik Weiguo Yin Condensed Matter Physics and Materials Science Division Brookhaven National LaboratoryUptonNY11973USA State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun130012China Department of Physics and Astronomy Stony Brook UniversityStony BrookNY11794USA

Ultrafast control of structural and electronic properties of various quantum materials has recently sparked great interest.In particular,photoinduced switching between distinct topological phases has been considered a promising route to realize quantum computers.Here we use first-principles and effective Hamiltonian methods to show that in ZrTe_(5),lattice distortions corresponding to all three types of zone-center infrared optical phonon modes can drive the system from a topological insulator to a Weyl semimetal.Thus achieved Weyl phases are robust,highly tunable,and one of the cleanest due to the proximity of the Weyl points to the Fermi level and a lack of other carriers.We also find that Berry curvature dipole moment,induced by the dynamical inversion symmetry breaking,gives rise to various nonlinear effects that oscillate with the amplitude of the phonon modes.These nonlinear effects present an ultrafast switch for controlling the Weyltronics-enabled quantum system.

关键词： quantum topological phonon

STUDY OF EFFECT OF SURFACE-OPTICAL phonon ON BIPOLARON IN QUANTUM-WELL WIRE

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Journal of Shanghai Jiaotong university(Science) 1997年第1期2卷 11-17页

作者：李泽民顾世洧林长净

ＳＴＵＤＹＯＦＥＦＦＥＣＴＯＦＳＵＲＦＡＣＥ┐ＯＰＴＩＣＡＬＰＨＯＮＯＮＯＮＢＩＰＯＬＡＲＯＮＩＮＱＵＡＮＴＵＭ┐ＷＥＬＬＷＩＲＥＣ．ＭＬｅ（李泽民）ＧｕＳｈｉｗｅｉ＊（顾世洧）Ｃ．ＣＬａｍ（林长净）（Ｄｅｐｔ．ｏｆ... 详细信息

ＳＴＵＤＹＯＦＥＦＦＥＣＴＯＦＳＵＲＦＡＣＥ┐ＯＰＴＩＣＡＬＰＨＯＮＯＮＯＮＢＩＰＯＬＡＲＯＮＩＮＱＵＡＮＴＵＭ┐ＷＥＬＬＷＩＲＥＣ．ＭＬｅ（李泽民）ＧｕＳｈｉｗｅｉ＊（顾世洧）Ｃ．ＣＬａｍ（林长净）（Ｄｅｐｔ．ｏｆＰｈｙｓｉｃｓａｎｄＭａｔｅｒｉａ...

关键词： quantum well wire bipolaron phonon superconductivity

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Understanding and tuning blue-to-near-infrared photon cutting by the Tm^(3+)/Yb^(3+) couple

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Light(Science & Applications) 2020年第1期9卷 992-1000页

作者： Dechao Yu Ting Yu Arnoldus Jvan Bunningen Qinyuan Zhang Andries Meijerink Freddy T.Rabouw Debye Institute for Nanomaterials Science Utrecht UniversityPrincetonplein 13584 CC UtrechtThe Netherlands State Key Laboratory of Luminescence Materials and Devices Institute of Optical Communication MaterialsSouth China University of TechnologyGuangzhou 510641China

Lanthanide-based photon-cutting phosphors absorb high-energy photons and‘cut’them into multiple smaller excitation quanta.These quanta are subsequently emitted,resulting in photon-conversion efficiencies exceeding unity.The photon-cutting process relies on energy transfer between optically active lanthanide ions doped in the phosphor.However,it is not always easy to determine,let alone predict,which energy-transfer mechanisms are operative in a particular phosphor.This makes the identification and design of new promising photon-cutting phosphors difficult.Here we unravel the possibility of using the Tm^(3+)/Yb^(3+) lanthanide couple for photon cutting.We compare the performance of this couple in four different host materials.Cooperative energy transfer from Tm^(3+)to Yb^(3+) would enable blue-to-near-infrared conversion with 200% efficiency.However,we identify phonon-assisted cross-relaxation as the dominant Tm^(3+)-to-Yb^(3+) energy-transfer mechanism in YBO_(3),YAG,and Y_(2)O_(3).In NaYF_(4),in contrast,the low maximum phonon energy renders phonon-assisted cross-relaxation impossible,making the desired cooperative mechanism the dominant energy-transfer pathway.Our work demonstrates that previous claims of high photon-cutting efficiencies obtained with the Tm^(3+)/Yb^(3+) couple must be interpreted with care.Nevertheless,the Tm^(3+)/Yb^(3+) couple is potentially promising,but the host material-more specifically,its maximum phonon energy-has a critical effect on the energy-transfer mechanisms and thereby on the photon-cutting performance.

关键词： couple phonon lanthanide

Lattice and spin dynamics in multiferroic BiFeO3 and RMnO3

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National Science Review 2019年第4期6卷 642-652页

作者： Yan Song Ben Xu Ce-Wen Nan School of Materials Science and Engineering and State Key Laboratory of New Ceramics and Fine ProcessingTsinghua University

The multiferroic materials Bi Fe O3 and RMn O3 exhibit coexisting magnetic order and ferroelectricity, and provide exciting platforms for new physics and potentially novel devices, where intriguing interplay between phonons and magnons exists. In this review, we paint a complete picture of bulk BiFeOtogether with orthorhombic and hexagonal RMnO(R includes rare-earth elements and yttrium) by summarizing the dynamics of spin and lattice and their magnetoelectric coupling, as well as the methods of controlling these characteristics under non-equilibrium conditions, from experimental and simulation perspectives.

关键词： multiferroics phonon magnon

Electron Density Response to phonon Dynamics in MgB2: An Indicator of Superconducting Properties

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Modeling and Numerical Simulation of Material Science 2018年第2期8卷 21-46页

作者： Jose A. Alarco Peter C. Talbot Ian D. R. Mackinnon Institute for Future Environments and Science and Engineering Faculty Queensland University of Technology (QUT) Brisbane Australia

Electron density differences resulting from atom displacement patterns aligned with phonon modes in MgB2 have been calculated using density functional theory (DFT). The extent of phonon anomalies, identified as indicators of the superconducting transition temperature, Tc, under a range of conditions in AlB2-type structures, reduce as boron atoms are displaced from their equilibrium positions along E2g mode directions. The Fermi energy for displacements along the directions of the E2g phonon mode accounts for changes in the covalent B-B bond electronic charge density. We applied differential atom displacements to show that the shifted σ band structure associated with the light effective mass became tangential to the Fermi level and that the Fermi surface undergoes a topological transition at a critical relative displacement of ~0.6% of the boron atoms from equilibrium. The difference in Fermi energies at this critical displacement and at the equilibrium position correspond to the superconducting energy gap. The net volume between tubular σ surfaces in reciprocal space correlated with the depth of the phonon anomaly and, by inference, it is a key to an understanding of superconductivity. This ab initioapproach offers a phenomenological understanding of the factors that determine Tc based on knowledge of the crystal structure.

关键词： Electron Density MgB2 phonon Dispersion Kohn Anomaly phonon Dynamics Superconducting Transition Temperature Superconductivity Mechanism

Surface phonon polaritonics made simple:great as plasmonics but lower losses

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Advanced Photonics 2019年第2期1卷 5-5页

作者： Jamie MFitzgerald Vincenzo Giannini Chalmers University of Technology GothenburgSweden Instituto de Estructura de la Materia Consejo Superior de Investigaciones CientíficasMadridSpain

The manipulation of light and,in particular,the ability to guide it in an extremely sub-diffraction fashion,is a long-standing goal in nanophotonics.This capability will open up a plethora of applications and can be extremely useful for enhancing light-matter interactions.Such goals are historically associated with metals near their plasma frequency;this is known as plasmonics.

关键词： phonon Surface metals

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Extrinsic electromagnetic fields, low frequency (phonon) vibrations, and control of cell function: a non-linear resonance system

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Journal of Biomedical Science and Engineering 2008年第3期1卷 152-156页

作者： Glen A. Gordon Electromagnetic Research and Education Foundation PO BOX 124 Port Gamble

Chou and Chen’s report in the 1970s suggested conformational protein adaptation (CPA) might be influenced by low frequency phonons acting as “a possible information system”. This report proposes the universal force of electromagnetism initiates the phonon system they cited as it per-turbs paramagnetic/diamagnetic dampers within the protein matrix to produce a quantized low frequency phonon signal series. (http://www.***.ilstu.edu/~ren/phononsims/page3.html) The signal series is iteratively processed by the protein beta sub-unit, the system, to posi-tion the alpha sub-unit, the outcome, a classic non-linear resonance system resulting in con-formational protein adaptation (CPA). CPA “priming” enables a secondary ATP/redox driven power system to complete cell activity. The evolutionary appearance of these two systems reflects their hierarchy: 1) a low energy phonon driven information control circuit governed by principles of physics that, along with proteins, may have preceded planet earth, and 2), an ATP/redox power completion circuit directed by principles of chemistry that evolved in living systems 1 billion or more years after earth formed.

关键词： Electromagnetic fields-forcer Paramag-netic/diamagnetic oscillators-damper phonon resonance-signal series Protein itera-tion-system Conformational adapta-tion-outcome

Violation of the T^(−1) Relationship in the Lattice Thermal Conductivity of Mg_(3)Sb_(2) with Locally Asymmetric Vibrations

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Research 2020年第1期2020卷 750-759页

作者： Yifan Zhu Yi Xia Yancheng Wang Ye Sheng Jiong Yang Chenguang Fu Airan Li Tiejun Zhu Jun Luo Christopher Wolverton GJeffrey Snyder Jianjun Liu Wenqing Zhang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Materials Genome Institute Shanghai UniversityShanghai 200444China Department of Materials Science and Engineering Northwestern UniversityIL 60208USA Max Planck Institute for Chemical Physics of Solids Dresden 01187Germany State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Department of Physics and Shenzhen Institute for Quantum Science&Engineering Southern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Lab for Computational Science and Materials Design and Shenzhen Municipal Key Lab for Advanced Quantum Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

Most crystalline materials follow the guidelines of T^(-1) temperature-dependent lattice thermal conductivity(κ_(L))at elevated temperatures.Here,we observe a weak temperature dependence ofκL in Mg_(3)Sb_(2),T^(-0:48) from theory and T-0:57 from measurements,based on a comprehensive study combining ab initio molecular dynamics calculations and experimental measurements on single crystal Mg_(3)Sb_(2).These results can be understood in terms of the so-called“phonon renormalization”effects due to the strong temperature dependence of the interatomic force constants(IFCs).The increasing temperature leads to the frequency upshifting for those low-frequency phonons dominating heat transport,and more importantly,the phononphonon interactions are weakened.In-depth analysis reveals that the phenomenon is closely related to the temperature-induced asymmetric movements of Mg atoms within MgSb_(4) tetrahedron.With increasing temperature,these Mg atoms tend to locate at the areas with relatively low force in the force profile,leading to reduced effective 3^(rd)-order IFCs.The locally asymmetrical atomic movements at elevated temperatures can be further treated as an indicator of temperature-induced variations of IFCs and thus relatively strong phonon renormalization.The present work sheds light on the fundamental origins of anomalous temperature dependence of κ_(L) in thermoelectrics.

关键词： phonon Conductivity Locally

THE EFFECT OF SPIN-WAVE AND phonon COUPLING ON THE INFRA-RED ABSORPTION SPECTRUM OF ANTIFERROMAGNETS

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Chinese Science Bulletin 1966年第4期24卷 159-161页

作者：朱砚磐王志强 Academia Sinica

Ⅰ. Because of the influence of the change in distance between ions on the exchange interaction,there exists coupling between spin-waves and phonons in magnetically ordered materials.Most of nonmetallic antiferromagnets are ionic crystals.As a result of the coupling between spin-waves and phonons, the radiation field, while exciting an optical phonon, may excite two

关键词： phonon Hamiltonian WAVE ionic exciting SPIN infra ordered Brillouin branch

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