Doublon dynamics of Bose-Fermi mixtures in optical lattices

Author
Abstract
We study the out-of-equilibrium dynamics of a dilute, lattice-confined Bose-Fermi mixture initialized in a highly excited state consisting of boson-fermion pairs (doublons) occupying single lattice sites. This system represents a paradigmatic case for studying relaxation dynamics in strongly correlated systems, and provides a versatile platform for studying thermalization and localization phenomena. We provide analytical expressions for the short-time decay of isolated doublons and small doublon clusters due to the competition between tunneling and interparticle interactions. We also discuss a mechanism for long-time decay that crucially depends on the quantum statistics of the particles constituting the doublon, namely, the conversion of pairs of neighboring doublons into an unpaired fermion and a site with a fermion and two bosons. Building on these insights, we develop a cluster expansion method to describe the dynamics in extended systems and compare it to numerically exact matrix product state simulations in one dimension. Finally, we discuss how our predictions can be observed in experiments with ultracold heteronuclear molecules.
Year of Publication
2019
Journal
Physical Review A
Volume
100
Date Published
2019-11
ISSN Number
2469-9926
URL
https://journals.aps.org/pra/abstract/10.1103/PhysRevA.100.053607
DOI
10.1103/PhysRevA.100.053607
JILA PI
Associated Institutes
Journal Article