Laboratoire de Physique Théorique
Toulouse - UMR 5152

Computing entanglement entropies in strongly interacting many-body systems in two or more dimensions is a notoriously difficult task. Recently, however, a Monte Carlo method based on Jarzynski’s nonequilibrium work equality has enabled highly efficient calculations in quantum spin systems [1]. I will show how this concept can be extended to determinental quantum Monte Carlo (DQMC) simulations of fermions, based on the decomposition introduced by T. Grover [2]. Here the nonequilibrium method entirely avoids the severe limitations faced by existing DQMC techniques, which manifest themselves quite differently from the spin case. As a benchmark study I will provide data from T=0 projector simulations of the honeycomb Hubbard model.

[1] J. D’Emidio, Entanglement Entropy from Nonequilibrium Work, Phys. Rev. Lett. 124, 110602 (2020)

[2] T. Grover, Entanglement of Interacting Fermions in Quantum Monte Carlo Calculations, Phys. Rev. Lett. 111, 130402 (2013)