Observation of topological electronic structure in quasi-1D superconductor TaSe3

TL;DR

This study identifies topological surface states in the quasi-1D superconductor TaSe3 using ARPES and STM, suggesting it as a stable, intrinsic topological superconductor candidate suitable for exploring Majorana modes.

Contribution

The paper provides the first systematic investigation of TaSe3's electronic structure, revealing its nontrivial topological surface states and superconducting gap, establishing it as a promising TSC candidate.

Findings

Identification of nontrivial topological surface states in TaSe3

Observation of a persistent superconducting gap on the surface

TaSe3 as a stable, exfoliable topological superconductor candidate

Abstract

Topological superconductors (TSCs), with the capability to host Majorana bound states that can lead to non-Abelian statistics and application in quantum computation, have been one of the most intensively studied topics in condensed matter physics recently. Up to date, only a few compounds have been proposed as candidates of intrinsic TSCs, such as doped topological insulator CuxBi2Se3 and iron-based superconductor FeTe0.55Se0.45. Here, by carrying out synchrotron and laser based angle-resolved photoemission spectroscopy (ARPES), we systematically investigated the electronic structure of a quasi-1D superconductor TaSe3, and identified the nontrivial topological surface states. In addition, our scanning tunneling microscopy (STM) study revealed a clean cleaved surface with a persistent superconducting gap, proving it suitable for further investigation of potential Majorana modes. These results prove TaSe3 as a stoichiometric TSC candidate that is stable and exfoliable, therefore a great platform for the study of rich novel phenomena and application potentials.