New class of topological superconductors protected by magnetic group symmetries

Chen Fang; Matthew J Gilbert; B Andrei Bernevig

doi:10.1103/PhysRevLett.112.106401

New class of topological superconductors protected by magnetic group symmetries

Phys Rev Lett. 2014 Mar 14;112(10):106401. doi: 10.1103/PhysRevLett.112.106401. Epub 2014 Mar 10.

Authors

Chen Fang¹, Matthew J Gilbert², B Andrei Bernevig³

Affiliations

¹ Department of Physics, University of Illinois, Urbana, Illinois 61801-3080, USA and Micro and Nanotechnology Laboratory, University of Illinois, Urbana, Illinois 61801, USA and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
² Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801, USA and Micro and Nanotechnology Laboratory, University of Illinois, Urbana, Illinois 61801, USA.
³ Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.

PMID: 24679310
DOI: 10.1103/PhysRevLett.112.106401

Abstract

We study a new type of three-dimensional topological superconductor that exhibits Majorana zero modes (MZM) protected by a magnetic group symmetry, a combined antiunitary symmetry composed of a mirror reflection and time reversal. This new symmetry enhances the noninteracting topological classification of a superconducting vortex from Z2 to Z, indicating that multiple MZMs can coexist at the end of one magnetic vortex of unit flux. Especially, we show that a vortex binding two MZMs can be realized on the (001) surface of a topological crystalline insulator SnTe with proximity induced BCS Cooper pairing, or in bulk superconductor InxSn1-xTe.