Ordered states of Rydberg-dressed ultracold quantum gases in optical lattices

研究了光学晶格中rydberg修饰的量子气体的远程有序态和准粒子激发。我们的非微扰理论方法，基于扩展的哈伯德模型，允许我们处理从远失谐弱修饰到共振里德伯激励的整个参数范围。它包括由穿衣引起的集体多体相互作用，这些相互作用超出了基于有效对势的描述。利用动力学平均场理论（DMFT），我们计算了超流体、超固体、密度和自旋有序相，以及它们的临界温度和熵。我们研究了几何晶格挫折对相图的影响，这有望导致新的相关状态。我们应用广义玻色子准粒子理论，确定了修饰系统的集体模式，如希格斯振幅模式和准粒子色散。耗散和消相对实际Rydberg激光激励方案的附加影响在Lindblad主方程中得到解决，该方程非摄动求解，使我们能够计算完全非平衡稳态相图，并寻找通过耗散稳定的新有序状态。

We investigate long-range ordered states and quasiparticle excitations of Rydberg-dressed quantum gases in optical lattices. Our non-perturbative theoretical approach, based on an extended Hubbard model, allows us to address the full parameter range from far-detuned weak dressing to resonant Rydberg excitation. It includes collective many-body interactions induced by dressing, which are beyond descriptions based on effective pair potentials. Using dynamical mean-field theory (DMFT), we calculate superfluid, supersolid, density- and spin-ordered phases, as well as their critical temperatures and entropies. We investigate the influence of geometric lattice frustration on the phase diagram, which is expected to lead to novel correlated states. We determine collective modes, such as the Higgs-amplitude mode, and quasiparticle dispersions of the dressed system, applying a generalized bosonic quasiparticle-theory. The additional influence of dissipation and dephasing for realistic Rydberg laser excitation schemes is addressed within a Lindblad master equation, solved non-perturbatively, which allows us to calculate the full out-of-equilibrium steady-state phase diagram, and to search for novel ordered states which are stabilized by dissipation.