EPJ Quantum Technol. (2015) 2: 1
https://doi.org/10.1140/epjqt15

Research

Thermalization of strongly interacting bosons after spontaneous emissions in optical lattices

¹ Department of Physics, JILA, NIST, University of Colorado, 440 UCB, Boulder, CO, 80309, USA
² Department of Physics, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, University of Munich, Munich, 80333, Germany
³ Theoretische Physik, ETH Zurich, Zurich, 8093, Switzerland
⁴ Department of Physics and SUPA, University of Strathclyde, Glasgow, G4 0NG, UK
⁵ Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA

^* e-mail: Johannes.Schachenmayer@gmail.com

Received: 1 August 2014
Accepted: 7 November 2014
Published online: 4 January 2015

Abstract

We study the out-of-equilibrium dynamics of bosonic atoms in a 1D optical lattice, after the ground-state is excited by a single spontaneous emission event, i.e. after an absorption and re-emission of a lattice photon. This is an important fundamental source of decoherence for current experiments, and understanding the resulting dynamics and changes in the many-body state is important for controlling heating in quantum simulators. Previously it was found that in the superfluid regime, simple observables relax to values that can be described by a thermal distribution on experimental time-scales, and that this breaks down for strong interactions (in the Mott insulator regime). Here we expand on this result, investigating the relaxation of the momentum distribution as a function of time, and discussing the relationship to eigenstate thermalization. For the strongly interacting limit, we provide an analytical analysis for the behavior of the system, based on an effective low-energy Hamiltonian in which the dynamics can be understood based on correlated doublon-holon pairs.