Mott transition in a cavity-boson system: A quantitative comparison between theory and experiment

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. 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 viable, 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, and verify that it only induces small systematic errors. The experimentally measured and theoretically predicted phase boundaries agree reasonably. We thus propose a new approach for the quantiative numerical determination of the superfluid-Mott-insulator phase boundary.

The Jaynes-Cummings model and its descendants

“…It is this combination of attractive and repulsive interaction at infinite length scales that makes the model qualitatively different from a regular Bose-Hubbard model -an interplay between short and infinite range interactions emerges. The phase diagram was studied theoretically in [1544,1545] and in [1546] for finite temperature, and experimentally in [1463,1464,1545]. We already know from our discussion above that in the superfluid regime, where the tunneling dominates over the onsite interaction (set by U ), the system is either in a regular superfluid or in a state reminiscent of a supersolid.…”

Superfluid-Mott insulator quantum phase transition in a cavity optomagnonic system

“…Given the precise control of coupling strengths, the properties of scalability and individual accessibility of coupled cavities [11][12][13][14], the Jaynes−Cummings Hubbard (JCH) model, which describes the dynamics of the coupled-cavity arrays with each embedded within a two-level atom has attracted tremendous attentions [15][16][17] in recent years. Based on the JCH model and extended JCH model, the superfluid-Mott insulator quantum phase transition of light reminiscent of the ones of atoms in the BH model are extensively simulated [18][19][20][21][22][23][24][25][26]. More importantly, the quantum phase transition of light depends crucially on the intrinsic atomphoton interaction in the JCH model, where the atomphoton coupling leads to the formation of repelled collective polaritonic excitations, and this on-site repulsive potential compete with the hopping of photons between neighbouring cavities.…”