Pair supersolid with atom-pair hopping on the state-dependent triangular lattice
Pair supersolid with atom-pair hopping on the state-dependent triangular lattice
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DOI：
10.1103/physrevb.88.174515
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发表时间：
2012-08
影响因子：
3.7
通讯作者：
Wanzhou Zhang;Ruoxi Yin;Yan-cheng Wang
中科院分区：
文献类型：
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作者：
Wanzhou Zhang;Ruoxi Yin;Yan-cheng Wang
本文系统地研究了三角晶格上三体约束下具有原子跳跃和原子对跳跃的扩展玻色-哈伯德模型。利用大规模量子蒙特卡罗模拟方法，研究了基态相图。我们发现，当改变原子跳跃和原子对跳跃的比例时，在原子超流相与原子对超流之间存在一级相变。一级相变在各种条件下保持不变。然后，我们专注于原子对跳跃，在现场排斥，最近邻排斥之间的相互作用。与现场排斥本，我们观察到莫特绝缘体和对超流体之间的一级跃迁驱动的对跳跃。当最近邻排斥作用开启时，在小原子对跳跃区出现了3种典型的固相，填充量分别为2/3、1和4/3。在小的在位排斥作用下，发现了稳定的对超固相。这是由于三体约束和对跳跃，这本质上使模型成为准硬核玻色子系统。因此，对超固态的出现是基于有序-无序机制，通过这种机制，硬核玻色子避免了三角晶格上的经典挫折。在没有在位排斥的情况下，除了粒子-空穴对称点以外，原子超流和对超流与对超固体之间的跃迁都是一级跃迁。在弱的在位排斥和原子跳跃作用下，双超固态和双超流态的相变是连续的。从固体到对超固体的转变是三维XY大学，动力学指数z = 1，关联指数nu = 0.67155。对超固体的热熔化属于二维伊辛大学。我们检查了对超固相的能量平衡和力学平衡。降低三体约束，没有发现对超固体，由于在经典极限下没有对固体的简并。描述了在态相关晶格上实现对隧穿的实验。
We systematically study an extended Bose-Hubbard model with atom hopping and atom-pair hopping in the presence of a three-body constraint on the triangular lattice. By means of large-scale quantum Monte Carlo simulations, the ground-state phase diagram is studied. We find a first-order transition between the atomic superfluid phase and the pair superfluid phase when the ratio of the atomic hopping and the atom-pair hopping is adapted. The first-order transition remains unchanged under various conditions. We then focus on the interplay among the atom-pair hopping, the on-site repulsion, and the nearest-neighbor repulsion. With on-site repulsion present, we observe first-order transitions between the Mott insulators and pair superfluid driven by the pair hopping. With the nearest-neighbor repulsion turning on, three typical solid phases with 2/3, 1, and 4/3 filling emerge at small atom-pair hopping region. A stable pair supersolid phase is found at small on-site repulsion. This is due to the three-body constraint and the pair hopping, which essentially make the model a quasihardcore boson system. Thus the pair supersolid state emerges basing on the order-by-disorder mechanism, by which hardcore bosons avoid classical frustration on the triangular lattice. Without on-site repulsion, the transitions between the pair supersolid and the atom superfluid or pair superfluid are first order, except for the particle-hole symmetric point. With weak on-site repulsion and atom hopping turning on, the transition between the pair supersolid and pair superfluid phase becomes continuous. The transition between solid and pair supersolid is three-dimensional XY university, with dynamical exponent z = 1 and correlation exponent nu = 0.671 55. The thermal melting of pair supersolid belongs to the two-dimensional Ising university. We check both energetic and mechanical balance of pair supersolid phase. Lowering the three-body constraint, no pair supersolid is found due to the absence of degeneracy of pair solids in classical limits. We describe the experimental realization of pair tunneling on state dependent lattice.