Band inversion and topology of the bulk electronic structure in FeSe0.45Te0.55

DOI: 10.1103/PhysRevB.101.245146

Authors: Himanshu Lohani (Technion-Israel Institute of Technology) , Tamaghna Hazra (Ohio State University) , Amit Ribak (Technion-Israel Institute of Technology) , Yuval Nitzav (Technion-Israel Institute of Technology) , Huixia Fu (Weizmann Institute of Science) , Binghai Yan (Weizmann Institute of Science) , Mohit Randeria (Ohio State University) , Amit Kanigel (Technion-Israel Institute of Technology)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 101

State: Published (Approved)
Published: June 2020
Diamond Proposal Number(s): 15822

Abstract: FeSe 0.45 Te 0.55 (FeSeTe) has recently emerged as a promising candidate to host topological superconductivity, with a Dirac surface state and signatures of Majorana bound states in vortex cores. However, correlations strongly renormalize the bands compared to electronic structure calculations, and there is no evidence for the expected bulk band inversion. We present here a comprehensive angle resolved photoemission (ARPES) study of FeSeTe as a function of photon energies ranging from 15–100 eV. We find that although the top of the bulk valence band shows essentially no k z dispersion, its normalized intensity exhibits a periodic variation with k z . We show, using ARPES selection rules, that the intensity oscillation is a signature of band inversion indicating a change in the parity going from Γ to Z . We also present a simple realistic tight-binding model which gives insight into ARPES observations. Thus we provide direct evidence for a topologically nontrivial bulk band structure that supports protected surface states.

Journal Keywords: Superconductivity; Topological materials; Angle-resolved photoemission spectroscopy

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Added On: 28/09/2022 09:22

Discipline Tags:

Superconductors Quantum Materials Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)