Quantum Monte Carlo study of positron lifetimes in solids

TL;DR

This paper introduces a quantum Monte Carlo method for calculating positron lifetimes in solids, providing more accurate, parameter-free predictions that enhance understanding of positron annihilation across various materials.

Contribution

It develops a novel quantum Monte Carlo approach that includes long-range correlations, offering an improved, parameter-free method for modeling positron lifetimes in solids.

Findings

Enhanced accuracy over previous methods

Good agreement with experimental data

Applicable to metals, insulators, and semiconductors

Abstract

We present an analysis of positron lifetimes in solids with unprecedented depth. Instead of modeling correlation effects with density functionals, we study positron-electron wave functions with long-range correlations included. This gives new insight in understanding positron annihilation in metals, insulators and semiconductors. By using a new quantum Monte Carlo approach for computation of positron lifetimes, an improved accuracy compared to previous computations is obtained for a representative set of materials when compared with experiment. Thus we present a method without free parameters as a useful alternative to the already existing methods for modeling positrons in solids.