Renyi Entanglement Entropy of Interacting Fermions Calculated Using Continuous-Time Quantum Monte Carlo Method

TL;DR

This paper introduces a novel algorithm leveraging continuous-time quantum Monte Carlo to efficiently compute the Renyi entanglement entropy in interacting fermion systems, effective across weak to strong interactions.

Contribution

The paper presents a new Monte Carlo-based algorithm that samples interaction corrections for entanglement entropy, improving efficiency in both weakly and strongly interacting fermion systems.

Findings

Efficient calculation of entanglement entropy in weakly interacting systems.

Effective performance for strongly interacting systems with Monte Carlo reweighting.

Application to charge-density-wave transition reveals entanglement signatures.

Abstract

We present a new algorithm for calculating the Renyi entanglement entropy of interacting fermions using the continuous-time quantum Monte Carlo method. The algorithm only samples interaction correction of the entanglement entropy, which by design ensures efficient calculation of weakly interacting systems. Combined with Monte Carlo reweighting, the algorithm also performs well for systems with strong interactions. We demonstrate the potential of this method by studying the quantum entanglement signatures of the charge-density-wave transition of interacting fermions on a square lattice.