Towards ab initio thermodynamics of the electron gas at strong degeneracy

TL;DR

This paper introduces a new computational approach, configuration PIMC, to study the uniform electron gas at high degeneracy, overcoming limitations of previous methods and providing benchmark energy data.

Contribution

The paper develops and tests the configuration PIMC method for high degeneracy regimes of the electron gas, extending beyond previous limitations.

Findings

Successful implementation and performance analysis of CPIMC for N=4 particles.

Benchmark total energy data for the model system.

Demonstration of CPIMC's potential for high degeneracy regimes.

Abstract

Recently a number of theoretical studies of the uniform electron gas (UEG) at finite temperature have appeared that are of relevance for dense plasmas, warm dense matter and laser excited solids and thermodynamic density functional theory simulations. In particular, restricted path integral Monte Carlo (RPIMC) results became available which, however, due to the Fermion sign problem, are confined to moderate quantum degeneracy, i.e. low to moderate densities. We have recently developed an alternative approach---configuration PIMC [T. Schoof {\em et al.}, Contrib. Plasma Phys. {\bf 51}, 687 (2011)] that allows one to study the so far not accessible high degeneracy regime. Here we present the first step towards UEG simulations using CPIMC by studying implementation and performance of the method for the model case of $N=4$ particles. We also provide benchmark data for the total energy.