Odd-Parity Pairing and Topological Superconductivity in a Strongly Spin-Orbit Coupled Semiconductor

Abstract

The existence of topological superconductors preserving time-reversal symmetry was recently predicted, and they are expected to provide a solid-state realization of itinerant massless Majorana fermions and a route to topological quantum computation. Their first concrete example, CuxBi2Se3, was discovered last year, but the search for new materials has so far been hindered by the lack of guiding principle. Here, we report point-contact spectroscopy experiments showing that the low-carrier-density superconductor Sn_{1-x}In_{x}Te is accompanied with surface Andreev bound states which, with the help of theoretical analysis, give evidence for odd-parity pairing and topological superconductivity. The present and previous finding of topological superconductivity in Sn_{1-x}In_{x}Te and CuxBi2Se3 demonstrates that odd-parity pairing favored by strong spin-orbit coupling is a common underlying mechanism for materializing topological superconductivity.

5 pages, 3 figures (paper proper) + 2 pages, 1 figure (supplemental material); final version accepted for publication in PRL; theoretical part has been significantly expanded

References in corpus (5)

• Classification of topological insulators and superconductors in three spatial dimensions
• The role of critical current on point contact Andreev Reflection spectrum between a normal metal and a superconductor
• Electrochemical synthesis and superconducting phase diagram of Cu_xBi2Se3
• Enhanced superconducting pairing interaction in indium-doped tin telluride
• Surface spectral function in the superconducting state of a topological insulator

Cited by in corpus (6)

• Half-Heusler topological insulators
• Superconducting properties of the In substituted Topological Crystalline Insulator, SnTe
• Revealing surface states in In-doped SnTe superconducting nanoplates with low bulk mobility
• Surface states and local spin susceptibility in doped three-dimensional topological insulators with odd-parity superconducting pairing symmetry
• Point-contact Andreev reflection spectroscopy of candidate topological superconductor Cu0.25Bi2Se3
• Surface states around a vortex in topological superconductors: Intersection of a surface and a vortex