Stability of a Nondegenerate Two--Component Weakly Coupled Plasma

TL;DR

This paper investigates the stability of a nondegenerate, weakly coupled two-component plasma by combining classical and quantum Monte Carlo methods, accounting for long-range interactions, and finds bound states are unlikely at low coupling.

Contribution

It introduces a method to accurately compute thermodynamic properties of nondegenerate plasmas with long-range effects using both CMC and PIMC simulations.

Findings

Bound state formation probability is very low at $\Gamma \,\le\, 0.01$

Thermodynamic properties agree with Debye-Hückel theory at low coupling

Bound states cause loss of N-convergence at higher coupling

Abstract

The paper discusses the problem of stability of a two-component plasma and proposes a consistent consideration of quantum and long-range effects to calculate the thermodynamic properties of such a plasma. We restrict ourselves by the case of a non-degenerate plasma to avoid the fermionic sign problem and consider the weakly coupled regime. Long-range interaction effects are taken into account using the angular-averaged Ewald potential (AAEP). To calculate thermodynamic properties, we apply both classical Monte Carlo (CMC) and path integral Monte Carlo (PIMC) methods. A special method is developed to correctly calculate potential energy in PIMC simulations with long-range interaction effects. Our theoretical estimations show that the probability of a bound state formation is very low at a coupling parameter $\Gamma~\le~0.01$, so both classical and quantum simulations give the same energy at $\Gamma~\leq~0.01$, and the thermodynamic limit coincides with the Debye--H\"uckel theory. At higher $\Gamma$, the $N$-convergence is lost due to the formation of bound states.