Topological superconductivity at the edge of transition-metal dichalcogenides

Gang Xu, Jing Wang, Binghai Yan, Xiao Liang Qi

Research output: Contribution to journalArticlepeer-review

Abstract

Time-reversal breaking topological superconductors are new states of matter which can support Majorana zero modes at the edge. In this Rapid Communication, we propose a different realization of one-dimensional topological superconductivity and Majorana zero modes. The proposed system consists of a monolayer of transition-metal dichalcogenides MX2 (M=Mo,W; X=S,Se) on top of a superconducting substrate. Based on first-principles calculations, we show that a zigzag edge of the monolayer MX2 terminated by a metal atom M has edge states with strong spin-orbit coupling and spontaneous magnetization. By proximity coupling with a superconducting substrate, topological superconductivity can be induced at such an edge. We propose NbS2 as a natural choice of substrate, and estimate the proximity induced superconducting gap based on first-principles calculation and a low energy effective model. As an experimental consequence of our theory, we predict that Majorana zero modes can be detected at the 120° corner of a MX2 flake in proximity to a superconducting substrate.

Original languageEnglish
Article number100505
JournalPhysical Review B
Volume90
Issue number10
DOIs
StatePublished - 12 Sep 2014
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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