Gigantic Surface Lifetime of an Intrinsic Topological Insulator
- Princeton Univ., NJ (United States). Joseph Henry Lab., Dept. of Physics; Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Princeton Univ., NJ (United States). Joseph Henry Lab., Dept. of Physics
- Univ. of Tokyo (Japan). Inst. for Solid State Physics (ISSP)
- Princeton Univ., NJ (United States). Dept. of Chemistry; Peking Univ., Beijing (China). International Center for Quantum Materials
- Univ. of California, Berkeley, CA (United States). Dept. of Physics
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Univ. of Maryland, College Park, MD (United States). Joint Quantum Inst. and Condensed Matter Theory Center, Dept. of Physics; Monash Univ., Melbourne, VIC (Australia). School of Physics
- Princeton Univ., NJ (United States). Dept. of Chemistry
- Princeton Univ., NJ (United States). Joseph Henry Lab., Dept. of Physics; Princeton Univ., NJ (United States). Princeton Center for Complex Materials
We report that the interaction between light and novel two-dimensional electronic states holds promise to realize new fundamental physics and optical devices. Here, we use pump-probe photoemission spectroscopy to study the optically excited Dirac surface states in the bulk-insulating topological insulator Bi2Te2Se and reveal optical properties that are in sharp contrast to those of bulk-metallic topological insulators. We observe a gigantic optical lifetime exceeding 4 μs (1 μs=10$${-}$$6 s) for the surface states in Bi2Te2Se, whereas the lifetime in most topological insulators, such as Bi2Se3, has been limited to a few picoseconds (1 ps=10$${-}$$12 s). Moreover, we discover a surface photovoltage, a shift of the chemical potential of the Dirac surface states, as large as 100 mV. Lastly, our results demonstrate a rare platform to study charge excitation and relaxation in energy and momentum space in a two-dimensional system.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Laboratory Directed Research and Development (LDRD) Program; National Science Foundation (NSF); Australian Research Council; Simons Foundation
- Grant/Contract Number:
- AC52-06NA25396; FG-02-05ER46200; AC03-76SF00098; FG02-07ER46352; SC0001911; AC02-05CH11231; GBMF4547; 26800165; DMR 1206513
- OSTI ID:
- 1334115
- Alternate ID(s):
- OSTI ID: 1214746
- Report Number(s):
- LA-UR-15-26947; PRLTAO
- Journal Information:
- Physical Review Letters, Vol. 115, Issue 11; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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