Path-integral Monte Carlo estimator for the dipole polarizability of quantum plasma

TL;DR

This paper introduces a path-integral Monte Carlo method to accurately compute the dipole polarizability of quantum plasmas, validated against analytical models and applicable in optical frequency regimes.

Contribution

The authors develop and validate a novel Monte Carlo estimator for dipole polarizability in quantum plasmas, incorporating both collective and one-particle autocorrelation functions.

Findings

Perfect match of collective response with analytical reference

Systematic analysis of physical and numerical parameters

Insights into the phenomenological Drude scattering model

Abstract

We present a path-integral Monte Carlo estimator for calculating the dipole polarizability of interacting Coulomb plasma in the long-wavelength limit, i.e., the optical region. We present comprehensive details and method validation studies for our approach based on both collective and one-particle dipole autocorrelation functions in the imaginary time. The simulation of thermal equilibrium in imaginary time has exact Coulomb interactions and Boltzmann quantum statistics. For reference, we use analytically continued Drude model as the long-wavelength limit of the Lindhard response. Our collective response shows perfect match to the analytical reference. The one-particle response is used in systematic studies of physical and numerical parameters, and to discuss the phenomenological Drude scattering model.