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 language | English |
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Article number | 100505 |
Journal | Physical Review B |
Volume | 90 |
Issue number | 10 |
DOIs | |
State | Published - 12 Sep 2014 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics