Z2 topological liquid of hard-core bosons on a kagome lattice at 1/3 filling
Z2 topological liquid of hard-core bosons on a kagome lattice at 1/3 filling
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DOI：
10.1103/physrevb.92.075141
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发表时间：
2015-08-26
影响因子：
3.7
通讯作者：
Pollmann, Frank
中科院分区：
文献类型：
--
作者：
Roychowdhury, Krishanu;Bhattacharjee, Subhro;Pollmann, Frank
我们考虑了存在短程排斥相互作用的Kagome晶格上的硬核玻色子，并着重讨论了填充因子1/3。在强相互作用极限下，低能激发可以用三角晶格上的量子全填充回路覆盖来描述。结合基于张量积态的方法和精确对角化技术，我们证明了系统存在一个扩展的Z(2)拓扑液相和一个拉提式相。后者破坏了晶格的旋转对称性。通过调节模型中适当的参数，我们研究了拓扑破缺相和对称破缺相之间的量子相变。我们使用到伊辛规范理论的映射来构造这种转变的临界理论，该理论预测了这种转变属于O(3)普适性类。
We consider hard-core bosons on the kagome lattice in the presence of short-range repulsive interactions and focus particularly on the filling factor 1/3. In the strongly interacting limit, the low-energy excitations can be described by the quantum fully packed loop coverings on the triangular lattice. Using a combination of tensor product state based methods and exact diagonalization techniques, we show that the system has an extended Z(2) topological liquid phase as well as a latti ce nematic phase. The latter breaks lattice rotational symmetry. By tuning appropriate parameters in the model, we study the quantum phase transition between the topological and the symmetry broken phases. We construct the critical theory for this transition using a mapping to an Ising gauge theory that predicts the transition to belong to the O(3) universality class.