Year: 2024
Type: article
Abstract: Ultrafast photoexcitation offers a novel approach to manipulating quantum materials. One of the long-standing goals in this field is to achieve optical control over topological properties. However, the impact on their electronic structures, which host gapless surface states, has yet to be directly observed. Here, using time- and angle-resolved photoemission spectroscopy, we visualize the photoinduced evolution of the band structure in Bi_{y}(Pb_{1-x}Sn_{x})_{1-y}Se(111) films from topological to trivial insulators. Following near-infrared ultrafast laser excitation, we observe that the topological surface state opens a substantial gap of up to 0.1 eV. Considering the topological phase diagram associated with lattice distortion and atomic displacement, we show that a uniaxial strain generated by the ultrafast optical pulse is sufficiently effective and strong for the observed topological phase transition. Our Letter highlights the potential of optical tuning of materials through laser excitation to control topological properties on ultrafast timescales.
Source: Physical Review Letters
Authors: Masataka Mogi, Dongsung Choi, Louis Primeau, Baiqing Lv, Doron Azoury, Yifan Su, Liang Fu, Yang Zhang, Nuh Gedik
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: U.S. Department of Energy, Gordon and Betty Moore Foundation, University of Tennessee, University of Tennessee, Knoxville, Materials Research Science and Engineering Center, Harvard University, Japan Society for the Promotion of Science, Japan Science and Technology Agency, Basic Energy Sciences, Precursory Research for Embryonic Science and Technology, Division of Materials Sciences and Engineering
OpenAlex ID: W4404961162