Coherent Lattice Vibrations in Mono- and Few-Layer WSe2
| Autor: | Ki-Ju Yee, Sonny H. Rhim, Jaesung Park, Tae Young Jeong, Dong-Hun Chae, Yong-Hoon Kim, Hyang Rok Lee, L. Debbichi, Donghan Lee, Byung Moon Jin, Yu Dong Jang, Suyong Jung |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Condensed matter physics Phonon Exciton Anharmonicity General Engineering General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Brillouin zone Condensed Matter::Materials Science Transition metal Condensed Matter::Superconductivity 0103 physical sciences Monolayer Condensed Matter::Strongly Correlated Electrons General Materials Science Time domain 010306 general physics 0210 nano-technology Excitation |
| Zdroj: | ACS nano. 10(5) |
| ISSN: | 1936-086X |
| Popis: | We report the observation of coherent lattice vibrations in mono- and few-layer WSe2 in the time domain, which were obtained by performing time-resolved transmission measurements. Upon the excitation of ultrashort pulses with the energy resonant to that of A excitons, coherent oscillations of the A1g optical phonon and longitudinal acoustic phonon at the M point of the Brillouin zone (LA(M)) were impulsively generated in monolayer WSe2. In multilayer WSe2 flakes, the interlayer breathing mode (B1) is found to be sensitive to the number of layers, demonstrating its usefulness in characterizing layered transition metal dichalcogenide materials. On the basis of temperature-dependent measurements, we find that the A1g optical phonon mode decays into two acoustic phonons through the anharmonic decay process. |
| Databáze: | OpenAIRE |
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