title: New class of topological superconductors protected by magnetic group symmetries.
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.
authors.affiliation: 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.
authors.forename: Chen
authors.initials: C
authors.lastname: Fang
authors.affiliation: 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.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Gilbert
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: B Andrei
authors.initials: BA
authors.lastname: Bernevig