First-principles quantum dynamics for fermions: Application to molecular dissociation

TL;DR

This paper introduces a Gaussian phase-space method to simulate the quantum dynamics of fermionic systems, specifically applied to molecular dissociation in ultracold gases, revealing correlation growth beyond mean-field theories.

Contribution

The paper presents a first-principles simulation technique for fermionic quantum dynamics, enabling benchmarking and validation of approximate models in strongly correlated fermionic systems.

Findings

Atom-atom pair correlations deviate from Wick's factorization over time.

Atom-molecule and molecule-molecule correlations increase, indicating strong correlations.

The method provides a benchmark for approximate dynamical approaches.

Abstract

We demonstrate that the quantum dynamics of a many-body Fermi-Bose system can be simulated using a Gaussian phase-space representation method. In particular, we consider the application of the mixed fermion-boson model to ultracold quantum gases and simulate the dynamics of dissociation of a Bose-Einstein condensate of bosonic dimers into pairs of fermionic atoms. We quantify deviations of atom-atom pair correlations from Wick's factorization scheme, and show that atom-molecule and molecule-molecule correlations grow with time, in clear departures from pairing mean-field theories. As a first-principles approach, the method provides benchmarking of approximate approaches and can be used to validate dynamical probes for characterizing strongly correlated phases of fermionic systems.