Dissociation dynamics of resonantly coupled bose-fermi mixtures in an optical lattice

TL;DR

This paper investigates the dissociation dynamics of bosonic molecules into fermionic atoms in an optical lattice, revealing a crossover from independent to cooperative behavior and identifying two types of self-trapping transitions.

Contribution

It introduces a mean-field analysis of dissociation dynamics in a resonantly-coupled Bose-Fermi Hubbard model, connecting it to well-known quantum optical models.

Findings

Dissociation dynamics governed by a spin-boson lattice Hamiltonian in strong fermion interactions.

Crossover from independent to cooperative dissociation regimes as tunneling increases.

Identification of coherent and incoherent self-trapping transitions depending on interaction-to-tunneling ratio.

Abstract

We consider the photodissociation of ground-state bosonic molecules trapped in an optical lattice potential into two-component fermionic atoms. The system is assumed to be described by a one-band resonantly-coupled Bose-Fermi Hubbard model. We show that in the strong fermion-fermion interaction limit the dissociation dynamics is governed by a spin-boson lattice Hamiltonian. In the framework of a mean-field analysis based on the Gutzwiller ansatz, we then examine the crossover of the dissociation from a regime of independent single-site dynamics to a regime of cooperative dynamics as the molecular tunneling increases. We also identify two types of self-trapping transitions, a {\it coherent} and an {\it incoherent} one, depending on the ratio of the repulsive molecule-molecule interaction strength to molecular tunneling. Finally, we show that in the limits of weak and strong intersite tunneling the mean-field solutions agree well with the results from the quantum optical Jaynes-Cummings and Tavis-Cummings models, respectively.