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Driven electronic states at the surface of a topological insulator

TitleDriven electronic states at the surface of a topological insulator
Publication TypeJournal Article
Year of Publication2013
AuthorsB. M. Fregoso, Y-H. Wang, N. Gedik, and V. M. Galitski
JournalPhysical Review B
Volume88
Issue15
Pagination155129
Date Published10/23/2013
Accession NumberWOS:000326091700002
KeywordsDirac Cone, Topological Insulator
Abstract

Motivated by recent photoemission experiments on the surface of topological insulators we compute the spectrum of driven topological surface excitations in the presence of an external light source. We completely characterize the spectral function of these nonequilibrium electron excitations for both linear and circular polarizations of the incident light. We find that in the latter case, the circularly polarized light gaps out the surface states, whereas linear polarization gives rise to an anisotropic metal with multiple Dirac cones. We compare the sizes of the gaps with recent pump-probe photoemission measurements and find good agreement. We also identify theoretically several new features in the time-dependent spectral function, such as shadow Dirac cones.

URLhttp://prb.aps.org/abstract/PRB/v88/i15/e155129
DOI10.1103/PhysRevB.88.155129