Superconducting Topological Surface States in Non-centrosymmetric Bulk Superconductor PbTaSe2
Syu-You Guan1,2, Peng-Jen Chen1,2, Ming-Wen Chu3, Raman Sankar2,3, Fangcheng Chou3, Horng-Tay Jeng2,4, Chia-Seng Chang1,2, Tien-Ming Chuang2*
1Department of Physics, National Taiwan University, Taipei, Taiwan
2Institute of Physics, Academia Sinica, Taipei, Taiwan
3Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan
4Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Tien-Ming Chuang,
The search for topological superconductors (TSCs) is one of the most urgent contemporary problems in condensed matter systems. TSCs are characterized by a full superconducting gap in the bulk and topologically protected gapless surface (or edge) states constituted of Majorana fermions. Within each vortex core of TSCs, there exist the zero energy Majorana bound states, which are predicted to exhibit non-Abelian statistics and to form the basis of the fault-tolerant quantum computation. So far, no stoichiometric bulk material exhibits the required topological surface states (TSSs) at Fermi level combined with fully gapped bulk superconductivity. By using quasiparticle scattering interference imaging with support of DFT calculation, we show PbTaSe2 as a promising candidate as a TSC.

Keywords: topological superconductor, scanning tunneling microscopy