Chin.Phys.Lett.  2017, Vol. 34 Issue (03): 036301    DOI: 10.1088/0256-307X/34/3/036301
 CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES |
Topological Phonon Modes in a Two-Dimensional Wigner Crystal
Wen-Cheng Ji1, Jun-Ren Shi1,2**
1International Center for Quantum Materials, Peking University, Beijing 100871
2Collaborative Innovation Center of Quantum Matter, Beijing 100871
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Abstract We investigate the spin–orbit coupling effect in a two-dimensional (2D) Wigner crystal. It is shown that sufficiently strong spin–orbit coupling and an appropriate sign of $g$-factor could transform the Wigner crystal to a topological phonon system. We demonstrate the existence of chiral phonon edge modes in finite size samples, as well as the robustness of the modes in the topological phase. We explore the possibility of realizing the topological phonon system in 2D Wigner crystals confined in semiconductor quantum wells/heterostructure. It is found that the spin–orbit coupling is too weak for driving a topological phase transition in these systems. It is argued that one may look for topological phonon systems in correlated Wigner crystals with emergent effective spin–orbit coupling.
Received: 09 December 2016      Published: 14 March 2017
 PACS: 63.20.-e (Phonons in crystal lattices) 73.21.-b (Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems)
Fund: Supported by the National Basic Research Program of China under Grant No 2015CB921101, and the National Natural Science Foundation of China under Grant No 11325416.
Issue Date: 14 March 2017
 Cite this article: Wen-Cheng Ji,Jun-Ren Shi 2017 Chin.Phys.Lett. 34 036301 URL: http://cpl.iphy.ac.cn/newweb/10.1088/0256-307X/34/3/036301       OR      http://cpl.iphy.ac.cn/newweb/Y2017/V34/I03/036301