Quantum phases of bosons in double-well optical lattices
Quantum phases of bosons in double-well optical lattices
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DOI：
10.1103/physreva.76.043606
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发表时间：
2007-05
影响因子：
2.9
通讯作者：
I. Danshita;James E. Williams;C. S. D. Melo;C. Clark
中科院分区：
文献类型：
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作者：
I. Danshita;James E. Williams;C. S. D. Melo;C. Clark
我们研究双阱光学晶格中玻色子的超流体和绝缘相，并重点关注目前在实验中可以使用的两条腿梯子的具体示例。我们使用平均场和时间演化块抽取技术获得零温度相图。我们发现，只有当链内跳跃与现场斥力相比足够小时，平均场方法才能描述正确的相边界。我们展示了相图对链间跳跃或双井之间倾斜的依赖性。我们发现单位填充时的莫特绝缘体相表现出作为倾斜参数函数的非单调行为，从而在莫特绝缘体和超流体相之间产生重入相变。最后，我们确定了在相应填充处分离绝缘相和超流体相的临界点，即发生 Berezinskii-Kosterlitz-Thouless 转变的临界点。
We study the superfluid and insulating phases of bosons in double-well optical lattices, and focus on the specific example of a two-legged ladder, which is currently accessible in experiments. We obtain the zero-temperature phase diagram using both mean-field and time-evolving block decimation techniques. We find that the mean-field approach describes the correct phase boundaries only when the intrachain hopping is sufficiently small in comparison to the on-site repulsion. We show the dependence of the phase diagram on the interchain hopping or tilt between double wells. We find that the Mott-insulator phase at unit filling exhibits a nonmonotonic behavior as a function of the tilt parameter, producing a reentrant phase transition between Mott insulator and superfluid phases. Finally, we determine the critical point separating the insulating and superfluid phases at commensurate fillings, where the Berezinskii-Kosterlitz-Thouless transition occurs.