Choi Wonjune, Lee Ki Hoon, Kim Yong Baek
Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada.
Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul National University, Seoul 08826, Korea.
Phys Rev Lett. 2020 Mar 20;124(11):117205. doi: 10.1103/PhysRevLett.124.117205.
Unambiguous identification of fractionalized excitations in quantum spin liquids has been a long-standing issue in correlated topological phases. Conventional spectroscopic probes, such as the dynamical spin structure factor, can only detect composites of fractionalized excitations, leading to a broad continuum in energy. Lacking a clear signature in conventional probes has been the biggest obstacle in the field. In this work, we theoretically investigate what kinds of distinctive signatures of fractionalized excitations can be probed in two-dimensional nonlinear spectroscopy by considering the exactly solvable Kitaev spin liquids. We demonstrate the existence of a number of salient features of the Majorana fermions and fluxes in two-dimensional nonlinear spectroscopy, which provide crucial information about such excitations.
在关联拓扑相中，量子自旋液体中分数化激发的明确识别一直是一个长期存在的问题。传统的光谱探测方法，如动态自旋结构因子，只能检测分数化激发的复合体，导致能量上出现宽泛的连续谱。在传统探测中缺乏清晰的信号一直是该领域最大的障碍。在这项工作中，我们通过考虑精确可解的 Kitaev 自旋液体，从理论上研究了在二维非线性光谱中可以探测到哪些分数化激发的独特信号。我们证明了二维非线性光谱中马约拉纳费米子和磁通的许多显著特征的存在，这些特征提供了有关此类激发的关键信息。
