Mott transition in a cavity-boson system: A quantitative comparison between theory and experiment
Rui Lin, Christoph Georges, Jens Klinder, Paolo Molignini, Miriam Büttner, Axel U. J. Lode, Ramasubramanian Chitra, Andreas Hemmerich, Hans Keßler
Abstract
The competition between short-range and cavity-mediated infinite-range interactions in a cavity-boson system leads to the existence of a superfluid phase and a Mott-insulator phase within the self-organized regime. In this work, we quantitatively compare the steady-state phase boundaries of this transition measured in experiments and simulated using the Multiconfigurational Time-Dependent Hartree Method for Indistinguishable Particles. To make the problem computationally feasible, we represent the full system by the exact many-body wave function of a two-dimensional four-well potential. We argue that the validity of this representation comes from the nature of both the cavity-atomic system and the Bose-Hubbard physics. Additionally, we show that the chosen representation only induces small systematic errors, and that the experimentally measured and theoretically predicted phase boundaries agree reasonably well. We thus demonstrate a new approach for the quantitative numerical modeling for the physics of the superfluid--Mott-insulator phase boundary.