Phase diagram topology of the Haldane-Hubbard-Coulomb model
Phase diagram topology of the Haldane-Hubbard-Coulomb model
复制标题
DOI：
10.1103/physrevb.99.121113
复制
发表时间：
2018-09
影响因子：
3.7
通讯作者：
I. Tupitsyn;N. Prokof’ev
中科院分区：
文献类型：
--
作者：
I. Tupitsyn;N. Prokof’ev
研究了半填充时手性相$\phi = \pi/2$与自旋$1/2$ Haldane模型相互作用的相图。考虑了现场和远程库仑排斥相互作用（haldane - hubard -Coulomb模型）。在过去，仅通过各种近似和有限尺寸的方法来解决现场相互作用$U$的问题，这些方法在数量和质量上产生了彼此不一致的结果。本文采用图解蒙特卡罗技术精确定位了$(\Delta, U)$ -平面上拓扑非平凡相的相变点，其中$\pm \Delta$为反演对称性破缺的现场能量，并确定了在适当的处理中不能忽略自能的动量依赖性。我们还发现，即使是适度的远程相互作用，通常在理论考虑中被抛弃，也会导致过渡线的显著变化。
We study the phase diagram of the interacting spin-$1/2$ Haldane model with chiral phase $\phi = \pi/2$ at half-filling. Both on-site and long-range Coulomb repulsive interactions (Haldane-Hubbard-Coulomb model) are considered. The problem with on-site interaction $U$ alone was addressed in the past by a variety of approximate and finite size methods that produced results in disagreement with each other both quantitatively and qualitatively. Here we employ the Diagrammatic Monte Carlo technique to accurately locate phase transition points to the topologically nontrivial phases in the $(\Delta, U)$-plane, where $\pm \Delta$ is the inversion symmetry breaking on-site energy, and establish that momentum dependence of self-energy cannot be neglected in the proper treatment. We also find that even modest long-range interactions, typically discarded in theoretical considerations, result in significant shifts of transition lines.