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

• Published in: Science bulletin (Beijing) Vol. 62; no. 12; pp. 852 - 856
• Main Authors: Lv, Yan-Feng, Wang, Wen-Lin, Zhang, Yi-Min, Ding, Hao, Li, Wei, Wang, Lili, He, Ke, Song, Can-Li, Ma, Xu-Cun, Xue, Qi-Kun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30-06-2017
• Subjects: Epitaxial β-Bi2Pd films; Majorana zero modes; Molecular beam epitaxy; Scanning tunneling microscopy; Topological superconductivity; 分子束外延生长; 变拓扑; 实验; 扫描隧道显微镜; 签名; 薄膜; 超导体; 超导电性; Molecular beam epitaxy; Majorana zero modes; Scanning tunneling microscopy; Epitaxial β-Bi2Pd films; Topological superconductivity
• ISSN: 2095-9273
• DOI: 10.1016/j.scib.2017.05.008

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 topolog- ically nontrivial superconductivity on a single material of β-Bi2Pd films grown by molecular beam epi- taxy. 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 super- conducting states, are identified at magnetic vortices. The superconductivity exhibits resistance to non- magnetic 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.