Observation of inverted band structure in the topological Dirac semimetal candidate CaAuAs

DOI: 10.1103/PhysRevB.102.041104

Authors: Kosuke Nakayama (Tohoku University; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST)) , Zhiwei Wang (University of Cologne) , Daichi Takane (Tohoku University) , Seigo Souma (Tohoku University) , Yuya Kubota (Tohoku University) , Yuki Nakata (Tohoku University) , Cephise Cacho (Diamond Light Source) , Timur Kim (Diamond Light Source) , Sandy Adhitia Ekahana (Swiss Light Source) , Ming Shi (Swiss Light Source) , Miho Kitamura (High Energy Accelerator Research Organization (KEK)) , Koji Horiba (High Energy Accelerator Research Organization (KEK)) , Hiroshi Kumigashira (High Energy Accelerator Research Organization (KEK); Tohoku University) , Takashi Takahashi (Tohoku University) , Yoichi Ando (University of Cologne) , Takafumi Sato (Tohoku University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 102

State: Published (Approved)
Published: July 2020
Diamond Proposal Number(s): 23799

Abstract: We have performed high-resolution angle-resolved photoemission spectroscopy of the ternary pnictide CaAuAs, which is predicted to be a three-dimensional topological Dirac semimetal (TDS). By accurately determining the bulk-band structure, we have revealed the coexistence of three-dimensional and quasi-two-dimensional Fermi surfaces with dominant hole carriers. The band structure around the Brillouin-zone center is characterized by an energy overlap between the hole and electron pockets, in excellent agreement with first-principles band-structure calculations. This indicates the occurrence of bulk-band inversion, supporting the TDS state in CaAuAs. Because of the high tunability in the chemical composition besides the TDS nature, CaAuAs provides a precious opportunity for investigating the quantum phase transition from TDS to other exotic topological phases.

Journal Keywords: Electronic structure; Topological materials; Semimetals; Angle-resolved photoemission spectroscopy

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Other Facilities: SIS X09LA at Swiss Light Source (SLS)

Added On: 29/07/2020 15:54

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)