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Fidelity as a marker of topological phase transitions in 2D Dirac materials
Author(s) -
Bolívar Juan Carlos,
Cordero Nicolas A.,
Nagy Ágnes,
Romera Elvira
Publication year - 2018
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.25674
Subject(s) - topological insulator , physics , topological order , electric field , zitterbewegung , silicene , gaussian , phase transition , condensed matter physics , topology (electrical circuits) , quantum mechanics , electron , quantum , graphene , mathematics , combinatorics
Silicene, as other 2D buckled structures, is a gapped Dirac material with intrinsic spin‐orbit coupling whose band structure can be controlled by applying a perpendicular electric field. It presents a topological phase transition from a topological insulator to a band insulator at the charge neutrality point. We present in this article a characterization of this phase transition by using fidelity of Loschmidt echoes when a magnetic and two slightly different electric fields are applied by considering the time evolution of two kinds of wave packets, one with a single Gaussian profile and the other with a double Gaussian profile creating a cat state. We also show that Zitterbewegung, classical, and revival Loschmidt periods diverge close to but not exactly at the charge neutrality point and explain this behavior.