Lin, Kai-Qiang and Ong, Chin Shen and Bange, Sebastian and Faria Junior, Paulo E. and Peng, Bo and Ziegler, Jonas D. and Zipfel, Jonas and Baeuml, Christian and Paradiso, Nicola and Watanabe, Kenji and Taniguchi, Takashi and Strunk, Christoph and Monserrat, Bartomeu and Fabian, Jaroslav and Chernikov, Alexey and Qiu, Diana Y. and Louie, Steven G. and Lupton, John M. (2021) Narrow-band high-lying excitons with negative-mass electrons in monolayer WSe2. NATURE COMMUNICATIONS, 12 (1): 5500. ISSN , 2041-1723
Full text not available from this repository. (Request a copy)Abstract
Monolayer transition-metal dichalcogenides (TMDCs) show a wealth of exciton physics. Here, we report the existence of a new excitonic species, the high-lying exciton (HX), in single-layer WSe2 with an energy of similar to 3.4 eV, almost twice the band-edge A-exciton energy, with a linewidth as narrow as 5.8 meV. The HX is populated through momentum-selective optical excitation in the K-valleys and is identified in upconverted photoluminescence (UPL) in the UV spectral region. Strong electron-phonon coupling results in a cascaded phonon progression with equidistant peaks in the luminescence spectrum, resolvable to ninth order. Ab initio GW-BSE calculations with full electron-hole correlations explain HX formation and unmask the admixture of upper conduction-band states to this complex many-body excitation. These calculations suggest that the HX is comprised of electrons of negative mass. The coincidence of such high-lying excitonic species at around twice the energy of band-edge excitons rationalizes the excitonic quantum-interference phenomenon recently discovered in optical second-harmonic generation (SHG) and explains the efficient Auger-like annihilation of band-edge excitons.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RESONANT RAMAN-SCATTERING; QUASI-PARTICLE; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Jaroslav Fabian Physics > Institute of Experimental and Applied Physics > Chair Professor Weiss > Group Christoph Strunk |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 12 Sep 2022 11:48 |
| Last Modified: | 12 Sep 2022 11:48 |
| URI: | https://pred.uni-regensburg.de/id/eprint/47195 |
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