论文标题
蜂窝状晶格上硬核玻色子的拓扑绝缘阶段
Weak topological insulating phases of hard-core-bosons on the honeycomb lattice
论文作者
论文摘要
我们研究了在沿晶格的不同Y层的现场电位上，在现场电位的存在下，在二维周期性蜂窝晶格上研究了硬核玻璃体的相位。使用分析计算支持的量子蒙特卡洛模拟，我们确定了一个弱拓扑绝缘子，其特征在于零贝里相，但非零浆果相，该阶段以潜在模式确定，以密度为1/4或3/4。此外，在1/2填充时观察到电荷密度波绝缘子，而中间密度的相图被超流相占据。进一步证明，弱拓扑绝缘子对任何数量的最近邻居的排斥以及弱的下一个最邻居的排斥力是可靠的。在光学晶格设置中，我们的模型的实验实现是可行的。
We study the phases of hard-core-bosons on a two-dimensional periodic honeycomb lattice in the presence of an on-site potential with alternating sign along the different y-layers of the lattice. Using quantum Monte Carlo simulations supported by analytical calculations, we identify a weak topological insulator, characterized by a zero Chern number but non-zero Berry phase, which is manifested at either density 1/4 or 3/4, as determined by the potential pattern. Additionally, a charge-density-wave insulator is observed at 1/2-filling, whereas the phase diagram at intermediate densities is occupied by a superfluid phase. The weak topological insulator is further shown to be robust against any amount of nearest-neighbor repulsion, as well as weak next-nearest-neighbor repulsion. The experimental realization of our model is feasible in an optical lattice setup.
