On the Sign Problem of the Fermionic Shadow Wave Function

TL;DR

This paper introduces new methods to reduce the sign problem in Fermionic Shadow Wave Function simulations within Variational Monte Carlo, enabling more accurate quantum simulations despite increased computational costs.

Contribution

The paper presents novel techniques that mitigate the sign problem in Fermionic Shadow Wave Functions, expanding their applicability in quantum Monte Carlo methods.

Findings

Variance is substantially reduced by the new methods.

Efficiency gain is limited due to increased computational cost.

Enables highly accurate quantum Monte Carlo simulations.

Abstract

We present a whole series of novel methods to alleviate the sign problem of the Fermionic Shadow Wave Function in the context of Variational Monte Carlo. The effectiveness of our new techniques is demonstrated on the example of liquid 3He. We found that although the variance is substantially reduced, the gain in efficiency is restricted by the increased computational cost. Yet, this development not only extends the scope of the Fermionic Shadow Wave Function, but also facilitates highly accurate Quantum Monte Carlo simulations previously thought not feasible.