中国物理B ›› 2019, Vol. 28 ›› Issue (4): 47801-047801.doi: 10.1088/1674-1056/28/4/047801

所属专题： SPECIAL TOPIC — Topological semimetals

• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇    下一篇

Optical investigation of topological semimetal SrMnSb2

Zi-Yang Qiu(邱子阳), Zhi-Yu Liao(廖知裕), Xiang-Gang Qiu(邱祥冈)   

  1. 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
  • 收稿日期:2019-01-23 修回日期:2019-02-15 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: Xiang-Gang Qiu E-mail:xgqiu@iphy.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11774400) and the National Key Basic Research Program of China (Grant Nos. 2015CB921102 and 2017YFA0302903).

Optical investigation of topological semimetal SrMnSb2

Zi-Yang Qiu(邱子阳)1,2, Zhi-Yu Liao(廖知裕)1,2, Xiang-Gang Qiu(邱祥冈)1,2,3   

  1. 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
  • Received:2019-01-23 Revised:2019-02-15 Online:2019-04-05 Published:2019-04-05
  • Contact: Xiang-Gang Qiu E-mail:xgqiu@iphy.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11774400) and the National Key Basic Research Program of China (Grant Nos. 2015CB921102 and 2017YFA0302903).

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摘要：

We investigate the temperature-dependent infrared spectroscopy of SrMnSb2, which is a semimetal with multiple Fermi surfaces. A notable blue shift of the plasma minimum in reflectivity upon cooling indicates that the carrier density varies with temperature. In the real part of the optical conductivity σ1(ω), a linearly-increased component which extrapolates to zero conductivity at finite frequency has been identified, which suggests dispersion of gapped Dirac band structures near the Fermi level. A two-Drude model, representing two different types of carriers, is introduced to describe the real part of optical conductivity. We separate the contributions of two-Drude model in dc conductivity, and demonstrate that the transport properties of SrMnSb2 are mainly affected by the narrow-Drude quasiparticles. Compared with the similar phenomena observed in CaMnSb2 and SrMnBi2, we can infer that the two-Drude model is an appropriate approach to investigate the multiband materials in AMnSb2 and AMnBi2 families.

关键词: infrared spectroscopy, topological material, Drude mode

Abstract:

We investigate the temperature-dependent infrared spectroscopy of SrMnSb2, which is a semimetal with multiple Fermi surfaces. A notable blue shift of the plasma minimum in reflectivity upon cooling indicates that the carrier density varies with temperature. In the real part of the optical conductivity σ1(ω), a linearly-increased component which extrapolates to zero conductivity at finite frequency has been identified, which suggests dispersion of gapped Dirac band structures near the Fermi level. A two-Drude model, representing two different types of carriers, is introduced to describe the real part of optical conductivity. We separate the contributions of two-Drude model in dc conductivity, and demonstrate that the transport properties of SrMnSb2 are mainly affected by the narrow-Drude quasiparticles. Compared with the similar phenomena observed in CaMnSb2 and SrMnBi2, we can infer that the two-Drude model is an appropriate approach to investigate the multiband materials in AMnSb2 and AMnBi2 families.

Key words: infrared spectroscopy, topological material, Drude mode

中图分类号:  (Infrared and Raman spectra)

  • 78.30.-j
78.40.Kc (Metals, semimetals, and alloys) 78.47.-p (Spectroscopy of solid state dynamics)