Electron localization properties in high pressure hydrogen at the liquid-liquid phase transition by Coupled Electron-Ion Monte Carlo

TL;DR

This study investigates the electronic localization and phase transition in high-pressure hydrogen using Coupled Electron-Ion Monte Carlo simulations, revealing a metal-insulator transition linked to structural changes.

Contribution

It provides detailed analysis of electron localization and phase transition mechanisms in high-pressure hydrogen through advanced Monte Carlo methods.

Findings

Abrupt change in electron momentum distribution indicating metal-insulator transition.

Structural transition from atomic to molecular fluid.

Changes in pair correlation functions at the phase transition.

Abstract

We analyze in detail the electronic properties of high pressure hydrogen around the liquid-liquid phase transition based on Coupled Electron-Ion Monte Carlo calculations. Computing the off-diagonal single particle density matrix and the momentum distribution we discuss localization properties of the electrons. The abrupt changes of these distributions indicate a metal to insulator transition occurring together with the structural transition from the atomic to molecular fluid. We further discuss the electron-proton and electron-electron pair correlation functions, which also change abruptly at the transition.