Robust wavefront dislocations of Friedel oscillations in gapped graphene

作     者：Shu-Hui Zhang Jin Yang Ding-Fu Shao Zhenhua Wu Wen Yang 

作者机构：College of Mathematics and Physics Beijing University of Chemical Technology Beijing 100029 China Beijing Computational Science Research Center Beijing 100193 China Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience University of Nebraska–Lincoln Lincoln Nebraska 68588-0299 USA Key Laboratory of Microelectronics Devices and Integrated Technology Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 China 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2021年第103卷第16期

页      面：L161407-L161407页

核心收录：

基　　金：Beijing Computational Science Research Center Colorado Society for Respiratory Care, CSRC National Natural Science Foundation of China, NSFC, (11504018, 11774021) National Key Research and Development Program of China, NKRDPC, (2017YFA0303400) National Safety Academic Fund, NSAF, (U1930402) 

主　　题：Geometric & topological phases Graphene Green's function methods 

摘      要：Friedel oscillation is a well-known wave phenomenon which represents the oscillatory response of electron waves to imperfection. By utilizing the pseudospin-momentum locking in gapless graphene, two recent experiments demonstrate the measurement of the topological Berry phase by corresponding to the unique number of wavefront dislocations in Friedel oscillations. Here, we study the Friedel oscillations in gapped graphene, in which the pseudospin-momentum locking is broken. Unusually, the wavefront dislocations do occur like that in gapless graphene, which requires immediate verification in the current experimental condition. The number of wavefront dislocations is ascribed to the invariant pseudospin winding number in gapped and gapless graphene. This study deepens the understanding of the correspondence between topological quantity and wavefront dislocations in Friedel oscillations and implies the possibility to observe the wavefront dislocations of Friedel oscillations in intrinsic gapped two-dimensional materials, e.g., transition metal dichalcogenides.