Competing quantum phases of hard-core bosons with tilted dipole-dipole interaction
Competing quantum phases of hard-core bosons with tilted dipole-dipole interaction
复制标题
具有倾斜偶极-偶极相互作用的硬核玻色子的竞争量子相位
DOI：
10.1103/physreva.102.053306
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发表时间：
2020-06
影响因子：
2.9
通讯作者：
Huan Wu;Wei-Lin Tu
中科院分区：
文献类型：
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作者：
Huan Wu;Wei-Lin Tu
这项工作讨论了由具有不同偏振角的偶极-偶极相互作用引起的硬核玻色子的不同量子相。我们考虑由于方晶格中现场玻色子的倾斜偏振而具有各向异性的两个最有影响力的主导项。为了确保这种截断的具体性，我们将通过簇平均场理论（CMFT）和无限投影纠缠对态（iPEPS）数值获得的相图与量子蒙特卡罗的长程相互作用模型的相图进行了比较。接下来，我们关注方位角固定为$\ensuremath{\phi}=\ensuremath{\pi}/4$的情况。使用平均场分析，其中量子自旋算子被 $c$ 数字取代，我们的目标是搜索底层相，尤其是超固体。我们的结果显示了主要在具有不同晶胞尺寸的两个有序相之间的竞争场景，其中一阶转变发生在它们之间。借助CMFT和变分iPEPS，可以更精确地确定平均场理论预测的相界。我们的发现阐明了可能存在的潜在超固相，这些超固相可能在强偶极原子的超冷实验中出现。此外，我们的结果表明，可以通过微调方形晶格中偶极子的偏振来实现有效的三角形光学晶格。
Different quantum phases of a hard-core boson induced by dipole-dipole interaction with varying angles of polarization are discussed in this work. We consider the two most influential leading terms with anisotropy due to the tilted polarization of the on-site boson in the square lattice. To ensure the concreteness of this truncation, we compare our phase diagrams, obtained numerically from the cluster mean-field theory (CMFT) and infinite projected entangled-pair state (iPEPS), with that of the long-range interacting model from quantum Monte Carlo. Next, we focus on the case where the azimuthal angle is fixed to $\ensuremath{\phi}=\ensuremath{\pi}/4$. Using the mean-field analysis where the quantum spin operators are replaced by $c$ numbers, we aim to search for the underlying phases, especially the supersolid. Our results show a competing scenario mainly between two ordered phases with different sizes of unit cell, where a first-order transition takes place in between them. With the help of the CMFT and variational iPEPS, the phase boundaries predicted by the mean-field theory are determined more precisely. Our discoveries elucidate the possible underlying supersolid phases which might be seen in the ultracold experiments with strongly dipolar atoms. Moreover, our results indicate that an effective triangular optical lattice can be realized by fine tuning the polarization of dipoles in a square lattice.