Structure and dynamics of electron-phonon coupled systems using neural quantum states

TL;DR

This paper introduces neural quantum states as a versatile tool for modeling electron-phonon systems, achieving accurate results across simple models and realistic material simulations, including spectral properties.

Contribution

It presents a general neural quantum state framework capable of accurately describing high-dimensional electron-phonon wave functions with minimal physical bias.

Findings

Accurately models various lattice electron-phonon systems.

Successfully computes real-frequency spectral properties.

Demonstrates applicability to ab initio material models.

Abstract

In this work, we use neural quantum states (NQS) to describe the high-dimensional wave functions of electron-phonon coupled systems. We demonstrate that NQS can accurately and systematically learn the underlying physics of such problems through a variational Monte Carlo optimization of the energy with minimal incorporation of physical information even in highly challenging cases. We assess the ability of our approach across various lattice model examples featuring different types of couplings. The flexibility of our NQS formulation is demonstrated via application to ab initio models parametrized by density functional perturbation theory consisting of electron or hole bands coupled linearly to dispersive phonons. We compute accurate real-frequency spectral properties of electron-phonon systems via a novel formalism based on NQS. Our work establishes a general framework for exploring diverse ground state and dynamical phenomena arising in electron-phonon systems, including the non-perturbative interplay of correlated electronic and electron-phonon effects in systems ranging from simple lattice models to realistic models of materials parametrized by ab initio calculations.