Stability and electronic properties of two-dimensional gallium

TL;DR

This paper computationally investigates the stability, structure, and superconducting properties of two-dimensional gallium (gallenene), revealing stable configurations and a critical temperature around 7 K, with substrate effects considered.

Contribution

It identifies stable low-energy structures of gallenene and evaluates their superconducting critical temperature using computational methods, expanding understanding of 2D metallic materials.

Findings

Stable low-energy gallenene structures identified

Critical temperature for superconductivity around 7 K

Substrate effects influence structural stability

Abstract

Two-dimensional metals offer intriguing possibilities to explore metallicity and other related properties in systems with reduced dimensionality. Here, following recent experimental reports of synthesis of two-dimensional metallic gallium (gallenene) on insulating substrates, we conduct a computational search of gallenene structures using the Particle Swarm Optimization algorithm, and identify stable low energy structures. Our calculations of the critical temperature for conventional superconductivity yield values $\sim 7$ K for gallenene. We also emulate the presence of the substrate by introducing the external confining potential and test its effect on the structures with unstable phonons.