@article{2dada902a75d4731a85d6ac5de278eab,
title = "Bandgap modulation in photoexcited topological insulator Bi2Te3 via atomic displacements",
abstract = "The atomic and electronic dynamics in the topological insulator (TI) Bi2Te3 under strong photoexcitation were characterized with time-resolved electron diffraction and time-resolved mid-infrared spectroscopy. Three-dimensional TIs characterized as bulk insulators with an electronic conduction surface band have shown a variety of exotic responses in terms of electronic transport when observed under conditions of applied pressure, magnetic field, or circularly polarized light. However, the atomic motions and their correlation between electronic systems in TIs under strong photoexcitation have not been explored. The artificial and transient modification of the electronic structures in TIs via photoinduced atomic motions represents a novel mechanism for providing a comparable level of bandgap control. The results of time-domain crystallography indicate that photoexcitation induces two-step atomic motions: first bismuth and then tellurium center-symmetric displacements. These atomic motions in Bi2Te3 trigger 10% bulk bandgap narrowing, which is consistent with the time-resolved mid-infrared spectroscopy results.",
author = "Masaki Hada and Katsura Norimatsu and Sei′ichi Tanaka and Sercan Keskin and Tetsuya Tsuruta and Kyushiro Igarashi and Tadahiko Ishikawa and Yosuke Kayanuma and Miller, {R. J.Dwayne} and Ken Onda and Takao Sasagawa and Koshihara, {Shin Ya} and Nakamura, {Kazutaka G.}",
note = "Funding Information: This work was mainly supported by the Japan Science Technology Agency (JST), PRESTO, for a project entitled Molecular technology and creation of new functions. K.O. acknowledges JST-PRESTO for the project Chemical conversion of light energy. K.G.N. and Y.K. acknowledge JST-CREST for the project of Enhancing Applications of Innovative Optical Science and Technologies by making Ultimate Use of Advanced Light Sources. S.-y.K. acknowledges Grants-in-Aid for Scientific Research (Grant No. 15H02103) from the Japan Society for the Promotion of Science and the Ministry of Education, Culture, Sports, Science and Technology. S.K. and R.J.D.M. were supported by the Max Planck Society. The authors acknowledge Dr. Dongfang Zhang at the Max Planck Institute for the Structure and Dynamics of Matter and Professor Masahiro Kitajima at the Tokyo Institute of Technology for discussions. Publisher Copyright: {\textcopyright} 2016 Author(s).",
year = "2016",
month = jul,
day = "14",
doi = "10.1063/1.4955188",
language = "English",
volume = "145",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics Publising LLC",
number = "2",
}