High-temperature superconductivity with nontrivial electronic topology in monolayer h-V2N3

Abstract

Two-dimensional (2D) topological superconductors not only provide a platform for exploring novel quantum physical phenomena but also play a significant role in the field of quantum computing. However, reports on 2D topological superconductors are quite scarce. Here, based on first-principles calculations, we study the superconductivity of a class of monolayer TMmXn (TM=V, Nb, Ta; X=C, N; m=2, 3; n=2, 3; m≠n) with P6¯m2 (No. 187) and P3¯m1 (No. 164) symmetries, referred to as h−TMmXn (No. 187) and t−TMmXn (No. 164), respectively. Among them, monolayer h−V2N3 is predicted to have the highest critical temperature Tc as high as 38.4 K and a superconducting gap of about 9 meV. The superconductivity of monolayer h−V2N3 mainly originates from the strong coupling between conduction electrons from the V 3d and N 2p orbitals near the Fermi level and the low-frequency V- and N-related phonons. Moreover, nontrivial Z2 band topology further demonstrates that monolayer h−V2N3 is a promising candidate for realizing 2D topological superconductivity. Our findings provide a robust platform to study the emergent phenomena in 2D topological superconductors.

Source-reported materials — not catalogue approval

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