准一维电荷密度波材料Ta_(2)NiSe_(7)的转角及变温拉曼光谱研究  

Angle-/temperature-dependence of Raman Scattering in Quasi-One-Dimensional Charge Density Wave Material Ta_(2)NiSe_(7)

作　　者：康飞龙 周颖 安超 张敏 杨昭荣 KANG Feilong;ZHOU Ying;AN Chao;ZHANG Min;YANG Zhaorong(Institutes of Physical Science and Information Technology,Anhui University,Hefei 23060l,China;Anhui Key Laboratory of Low-Energy Quantum Materials and Devices,High Magnetic Field Laboratory,HFIPS,Chinese Academy of Sciences,Hefei 230031,China)

机构地区：[1]安徽大学物质科学与信息技术研究院,合肥230601 [2]中国科学院合肥物质科学研究院,强磁场科学中心,低功耗量子材料与器件安徽省重点实验室,合肥230031

出　　处：《低温物理学报》2024年第1期18-26,共9页Low Temperature Physical Letters

基　　金：国家重点基础研究发展计划(批准号:2023YFA1406102,2022YFA1602603);国家自然科学基金(批准号:12204004,12374049,1200400);安徽省高校自然科学研究重点项目(批准号:KJ2021A0068,KJ2021A0064);安徽省自然科学基金(批准号:2308085QA18);中国科学院重大科学基础设施基础研究计划(批准号:JZHKYPT-2021-08)资助的课题。

摘　　要：近年来,低维过渡金属硫族化合物Ta_(2)NiSe_(7)因其独特的电荷密度波和特殊的拓扑能带结构而引起广泛关注.本文利用拉曼光谱技术对准一维电荷密度波材料Ta_(2)NiSe_(7)的声子模式进行了系统研究.角度依赖的偏振拉曼光谱实验表明室温下可以观测到19个拉曼峰,且所有观察到的拉曼模式强度随样品旋转呈周期性变化,这意味着Ta_(2)NiSe_(7)具有较高的面内各向异性.通过群论分析,我们确定了拉曼峰的具体模式为Ag和Bg两种原子振动模式.在温度依赖的偏振拉曼光谱测量中,我们在低温下还观察到了新的声子峰,推测与电荷密度波结构调制引起的晶格畸变有关.本研究提供了对Ta_(2)NiSe_(7)声子振动的全面理解,这可能为进一步研究电荷密度波与声子振动之间的关联提供参考意义.Recently,the low-dimensional transition metal chalcogenide(TMC)Ta_(2)NiSe_(7)has attracted widespread attention due to its unique charge density wave(CDW)and special topological band structure.Here,we present a systematic study of phonon modes in a quasi-one-dimensional CDW material Ta_(2)NiSe_(7),by Raman spectroscopy.The angle-dependent polarized Raman scattering spectroscopy measurements revealed the presence of 19 Raman peaks at room temperature.The intensity of all observed Raman modes exhibited periodic variations as the sample was rotated,indicating a high in-plane anisotropy in Ta_(2)NiSe_(7).Further group theory analysis allowed us to identify the specific modes of the Raman peaks as two vibration modes,namely Ag and Bg.Based on temperature-dependent polarized Raman scattering measurements,we observe a new Raman peak at low temperatures,which can be attributed to the lattice distortions induced by charge density wave structural modulation.This study provides a comprehensive understanding of the phonon vibrations in Ta_(2)NiSe_(7),and can offer valuable insights for further exploring the correlation between charge density wave and phonon vibration.

关 键 词：拉曼散射 Ta_(2)NiSe_(7) 准一维材料 电荷密度波 

分 类 号：O657.37[理学—分析化学] TB34[理学—化学]