No sign problem in one-dimensional path integral Monte Carlo simulation of fermions: A topological proof.

Chin, Siu A · Phys Rev E · 2023

basic_science · Level V

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Abstract

This paper shows that, in one dimension, due to its topology, a closed-loop product of short-time propagators is always positive, despite the fact that each antisymmetric free fermion propagator can be of either sign.