First-principles estimation of the superconducting transition temperature of a metallic hydrogen liquid

TL;DR

This paper introduces a first-principles method using the stochastic path-integral approach within the PAW framework to estimate the superconducting transition temperature of metallic hydrogen liquids, confirming their potential for superconductivity.

Contribution

The authors generalize Liu et al.'s formalism to the PAW method and propose a new overlap operator formula, enabling accurate $T_c$ estimation for liquid metals.

Findings

Metallic hydrogen liquids can be superconducting.

The implementation confirms Liu et al.'s prediction.

The method improves accuracy in $T_c$ estimation.

Abstract

We present a first-principles implementation of the stochastic path-integral approach proposed by Liu et al. [H. Liu, Y. Yuan, D. Liu, X.-Z. Li, and J. Shi, Phys. Rev. Research 2, 013340 (2020)] for estimating the superconducting transition temperature ($T_c$) of a liquid. The implementation is based on the all-electron projector-augmented-wave (PAW) method. We generalize Liu et al.'s formalism to accommodate the pseudo-description of electron states in the PAW method. A formula for constructing the overlap operator of the PAW method is proposed to eliminate errors due to the incompleteness of a pseudo-basis set. We apply the implementation to estimate $T_c$'s of metallic hydrogen liquids. It confirms Liu et al.'s prediction that metallic hydrogen can form a superconducting liquid.