Optical investigation of topological semimetal SrMnSb2

• 来源期刊: 中国物理B（英文版）
• 关键词: infrared spectroscopy topological material Drude mode
• 年，卷（期）: 2019,（4）
• 页码范围: 47-50
• 页数: 4页
• 语种: 英文
• DOI: 10.1088/1674-1056/28/4/047801

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.