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arXiv 2008.08019cond-mat.str-el
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量子临界时的多临界拓扑跃迁

Multi-critical topological transition at quantum criticality

Ranjith R Kumar, Y R Kartik, S Rahul, Sujit Sarkar

摘要:

无带隙相之间拓扑量子相变的研究和表征是近年来拓扑态研究的热点之一。考虑一维三自旋相互作用的横场伊辛模型,在该模型的一条临界线上观察到了无带隙相之间的拓扑跃迁。我们研究了这些无间隙相位的不同性质,并表明它们属于不同的普适类。拓扑不变数(缠绕数)表征了参数空间不同区域的不同拓扑相。我们观察到两个多临界点的证据,一个是拓扑平凡的,另一个是拓扑活动的。在Lifshitz普适类中,临界线上的无隙相之间的拓扑量子相变通过非平凡的多临界点发生。计算和分析了多临界点附近Wannier态关联函数的行为,证实了无带隙相之间的拓扑转变。通过能量色散分析,我们证明了洛伦兹不变性在这个多临界点的崩溃。我们还表明,标度理论和曲率函数重整化群也可以有效地用于理解无隙相之间的拓扑量子相变。我们所研究的模型哈密顿量更适用于无隙激发的系统,传统的拓扑量子相变概念在此失效。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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