High-Throughput DFT-Based Discovery of Next Generation Two-Dimensional (2D) Superconductors

TL;DR

This study employs high-throughput DFT calculations to identify and analyze potential 2D superconductors, discovering new materials with transition temperatures above 5 K and validating some results through experiments.

Contribution

It introduces a systematic high-throughput DFT workflow for discovering 2D superconductors and reports new candidate materials with high transition temperatures.

Findings

Identified 34 stable 2D superconductors with $T_c$ above 5 K.

Discovered Mg$_2$B$_4$N$_2$ with $T_c$ of 21.8 K.

Validated some predictions with experimental measurements.

Abstract

High-throughput density functional theory (DFT) calculations allow for a systematic search for conventional superconductors. With the recent interest in two-dimensional (2D) superconductors, we used a high-throughput workflow to screen over 1,000 2D materials in the JARVIS-DFT database and performed electron-phonon coupling calculations, using the McMillan-Allen-Dynes formula to calculate the superconducting transition temperature ($T_c$) for 165 of them. Of these 165 materials, we identify 34 dynamically stable structures with transition temperatures above 5 K, including materials such as W$_2$N$_3$, NbO$_2$, ZrBrO, TiClO, NaSn$_2$S$_4$, Mg$_2$B$_4$C$_2$ and the previously unreported Mg$_2$B$_4$N$_2$ ($T_c$ = 21.8 K). Finally, we performed experiments to determine the $T_c$ of selected layered superconductors (2H-NbSe$_2$, 2H-NbS$_2$, ZrSiS, FeSe) and discuss the measured results within the context of our DFT results. We aim that the outcome of this workflow can guide future computational and experimental studies of new and emerging 2D superconductors by providing a roadmap of high-throughput DFT data.