Bose-Hubbard model: Relation between driven-dissipative steady states and equilibrium quantum phases

作者：Le Boite Alexandre^*; Orso Giuliano; Ciuti Cristiano

来源：Physical Review A, 2014, 90(6): 063821.

DOI：10.1103/PhysRevA.90.063821

We present analytical solutions for the mean-field master equation of the driven-dissipative Bose-Hubbard model for cavity photons, in the limit of both weak pumping and weak dissipation. Instead of pureMott-insulator states, we find statistical mixtures with the same second-order coherence g((2))(0) as a Fock state with n photons, but a mean photon number of n/2. These mixed states occur when n pump photons have the same energy as n interacting photons inside the nonlinear cavity and survive up to a critical tunneling coupling strength, above which a crossover to a classical coherent state takes place. We also explain the origin of both antibunching and superbunching predicted by P-representation mean-field theory at higher pumping and dissipation. In particular, we show that the strongly correlated region of the associated phase diagram cannot be described within the semiclassical Gross-Pitaevskii approach.

• 出版日期2014-12-15