Observation of a superradiant Mott insulator in the Dicke-Hubbard model

TL;DR

This paper reports the experimental observation of a superradiant Mott insulator phase in a system combining the bosonic Hubbard and Dicke models within an optical cavity, revealing novel quantum phases.

Contribution

It introduces the first realization of a superradiant Mott insulator in a cavity-mediated extended Hubbard model, merging two fundamental quantum models.

Findings

Identification of a superradiant Mott insulator phase

Observation of both coherent superfluid and incoherent Mott phases

Evidence of cavity-mediated infinite range interactions

Abstract

It is well known that the bosonic Hubbard model possesses a Mott insulator phase. Likewise, it is known that the Dicke model exhibits a self-organized superradiant phase. By implementing an optical lattice inside of a high finesse optical cavity both models are merged such that an extended Hubbard model with cavity-mediated infinite range interactions arises. In addition to a normal superfluid phase, two superradiant phases are found, one of them coherent and hence superfluid and one incoherent Mott insulating.