Two-dimensional transition metal selenides family M2Se: A platform for superconductivity, band topology, and charge density waves

TL;DR

This study introduces a new family of 2D transition metal selenides (M2Se) with diverse quantum properties, including superconductivity, topological states, and charge density waves, discovered through high-throughput screening.

Contribution

The paper reports the discovery and characterization of 58 candidate 2D M2Se materials, identifying stable, metallic, superconducting, topological, and magnetic properties, expanding the family of 2D quantum materials.

Findings

10 stable M2Se materials identified

8 exhibit superconductivity, 4 are topological superconductors

8 show charge density wave behavior

Abstract

MXenes and MBenes, which are two-dimensional (2D) transition metal carbides/nitrides and borides, have been extensively studied for their impressive properties. Recently, we reported a family of transition metal sulfides MSene (M2S) with rich properties [Phys. Rev. B 111, L041404 (2025)], it is worth studying whether selenides with similar structure also have rich properties. In this work, through high-throughput screening, we present a novel family of 2D transition metal selenides, M2Se. In this family, there are fifty-eight candidate materials, of which ten are stable and metallic. Notably, eight exhibit superconductivity, among which four are superconducting topological metals. Besides, eight show charge density wave (CDW) behavior, among which five also exhibit antiferromagnetism. It is revealed that CDW originates from electron-phonon coupling rather than Fermi surface nesting. Moreover, strain can be applied to regulate the competition between CDW and superconductivity. Our findings reveal the rich properties of superconductivity, band topology, CDW, and magnetism in M2Se, providing a new platform for the controllable integration of multifunctional quantum states.