论文标题
量子关键时的多临界拓扑过渡
Multi-critical topological transition at quantum criticality
论文作者
论文摘要
无间隙相之间拓扑量子相变的研究和表征是物质拓扑状态的最新研究兴趣之一。我们考虑在一个维度上具有三个自旋相互作用的横向场模型,并在该模型的关键线之一上观察到无间隙相之间的拓扑跃迁。我们研究了这些无间隙阶段的独特性质,并表明它们属于不同的普遍性类别。拓扑数(绕组数)表征了不同参数空间状态的不同拓扑阶段。我们观察到两个多临界点的证据,一个在拓扑上是微不足道的,另一个是拓扑主动的。临界线上无间隙相之间的拓扑量子相变是通过Lifshitz普遍性类别的非平凡的多临界点发生的。我们计算和分析靠近多临界点的Wannier状态相关函数的行为,并确认无间隙相之间的拓扑转变。我们通过能量分散分析在这个多临界点显示了Lorentz不变性的分解。我们还表明,缩放理论和曲率函数重新归一化组也可以有效地用于理解无间隙相之间的拓扑量子相变。我们研究的模型汉密尔顿模型更适用于具有无间隙激发的系统,在这种系统中,拓扑量子相变的常规概念失败了。
The investigation and characterization of topological quantum phase transition between gapless phases is one of the recent interest of research in topological states of matter. We consider transverse field Ising model with three spin interaction in one dimension and observe a topological transition between gapless phases on one of the critical lines of this model. We study the distinct nature of these gapless phases and show that they belong to different universality classes. The topological invariant number (winding number) characterize different topological phases for the different regime of parameter space. We observe the evidence of two multi-critical points, one is topologically trivial and the other one is topologically active. Topological quantum phase transition between the gapless phases on the critical line occurs through the non-trivial multi-critical point in the Lifshitz universality class. We calculate and analyze the behavior of Wannier state correlation function close to the multi-critical point and confirm the topological transition between gapless phases. We show the breakdown of Lorentz invariance at this multi-critical point through the energy dispersion analysis. We also show that the scaling theories and curvature function renormalization group can also be effectively used to understand the topological quantum phase transitions between gapless phases. The model Hamiltonian which we study is more applicable for the system with gapless excitations, where the conventional concept of topological quantum phase transition fails.