Háskóli ÍslandsUniversity of IcelandPervishko, Anastasiia A.Yudin, DmitryShelykh, Ivan2019-03-152019-03-152018-02-16Pervishko, A. A., Yudin, D., & Shelykh, I. A. (2018). Impact of high-frequency pumping on anomalous finite-size effects in three-dimensional topological insulators. Physical Review B, 97(7), 075420. doi:10.1103/PhysRevB.97.0754202469-99502469-9969 (eISSN)https://hdl.handle.net/20.500.11815/1054Publisher's version (útgefin grein)Lowering of the thickness of a thin-film three-dimensional topological insulator down to a few nanometers results in the gap opening in the spectrum of topologically protected two-dimensional surface states. This phenomenon, which is referred to as the anomalous finite-size effect, originates from hybridization between the states propagating along the opposite boundaries. In this work, we consider a bismuth-based topological insulator and show how the coupling to an intense high-frequency linearly polarized pumping can further be used to manipulate the value of a gap. We address this effect within recently proposed Brillouin-Wigner perturbation theory that allows us to map a time-dependent problem into a stationary one. Our analysis reveals that both the gap and the components of the group velocity of the surface states can be tuned in a controllable fashion by adjusting the intensity of the driving field within an experimentally accessible range and demonstrate the effect of light-induced band inversion in the spectrum of the surface states for high enough values of the pump.075420eninfo:eu-repo/semantics/openAccessBand gapLight-matter interactionSpin-orbit couplingTopological insulatorsCondensed Matter & Materials PhysicsGrannfræðiÞéttefnisfræðiinfo:eu-repo/semantics/articlePhysical Review B10.1103/PhysRevB.97.075420