Experimental signature of topological superconductivity and Majorana zero modes on β-Bi2Pd thin films

Yan-Feng Lv; Wen-Lin Wang; Yi-Min Zhang; Hao Ding; Wei Li; Lili Wang; Ke He; Can-Li Song; Xu-Cun Ma; Qi-Kun Xue

doi:10.1016/j.scib.2017.05.008

Experimental signature of topological superconductivity and Majorana zero modes on β-Bi₂Pd thin films

Sci Bull (Beijing). 2017 Jun 30;62(12):852-856. doi: 10.1016/j.scib.2017.05.008. Epub 2017 May 11.

Authors

Yan-Feng Lv¹, Wen-Lin Wang¹, Yi-Min Zhang¹, Hao Ding¹, Wei Li², Lili Wang², Ke He², Can-Li Song³, Xu-Cun Ma², Qi-Kun Xue⁴

Affiliations

¹ State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
² State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.
³ State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center of Quantum Matter, Beijing 100084, China. Electronic address: clsong07@mail.tsinghua.edu.cn.
⁴ State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center of Quantum Matter, Beijing 100084, China. Electronic address: qkxue@mail.tsinghua.edu.cn.

PMID: 36659319
DOI: 10.1016/j.scib.2017.05.008

Abstract

The search for Majorana fermions in topological superconductors is one of paramount research targets in physics today. Using a cryogenic scanning tunneling microscopy, we here report the signature of topologically nontrivial superconductivity on a single material of β-Bi₂Pd films grown by molecular beam epitaxy. The superconducting gap associated with spinless odd-parity pairing opens on the surface and appears much larger than the bulk one due to the Dirac-fermion enhanced parity mixing of surface pair potential. Zero bias conductance peaks, probably from Majorana zero modes supported by such superconducting states, are identified at magnetic vortices. The superconductivity exhibits resistance to nonmagnetic defects, characteristic of time-reversal-invariant topological superconductors. Our study reveals β-Bi₂Pd as a prime platform to generate, manipulate and braid Majorana zero modes for quantum computation.

Keywords: Epitaxial β-Bi(2)Pd films; Majorana zero modes; Molecular beam epitaxy; Scanning tunneling microscopy; Topological superconductivity.