Merkl, Philipp and Mooshammer, Fabian and Brem, Samuel and Girnghuber, Anna and Lin, Kai-Qiang and Wee, Leonard and Liebich, Marlene and Yong, Chaw-Keong and Gillen, Roland and Maultzsch, Janina and Lupton, John M. and Malic, Ermin and Huber, Rupert (2020) Twist-tailoring Coulomb correlations in van der Waals homobilayers. NATURE COMMUNICATIONS, 11 (1): 2167. ISSN 2041-1723,
Full text not available from this repository. (Request a copy)Abstract
The recent discovery of artificial phase transitions induced by stacking monolayer materials at magic twist angles represents a paradigm shift for solid state physics. Twist-induced changes of the single-particle band structure have been studied extensively, yet a precise understanding of the underlying Coulomb correlations has remained challenging. Here we reveal in experiment and theory, how the twist angle alone affects the Coulomb-induced internal structure and mutual interactions of excitons. In homobilayers of WSe2, we trace the internal 1s-2p resonance of excitons with phase-locked mid-infrared pulses as a function of the twist angle. Remarkably, the exciton binding energy is renormalized by up to a factor of two, their lifetime exhibits an enhancement by more than an order of magnitude, and the exciton-exciton interaction is widely tunable. Our work opens the possibility of tailoring quasiparticles in search of unexplored phases of matter in a broad range of van der Waals heterostructures. The crystallographic orientation of monolayers in van der Waals multi-layers controls their electronic and optical properties. Here the authors show how the twist angle affects Coulomb correlations governing the internal structure and the mutual interaction of excitons in homobilayers of WSe2.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | INDIRECT INTERLAYER EXCITONS; BANDGAP RENORMALIZATION; MOMENTUM; VALLEY; SPIN; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Rupert Huber Physics > Institute of Experimental and Applied Physics > Chair Professor Lupton > Group John Lupton |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 26 Mar 2021 11:08 |
| Last Modified: | 26 Mar 2021 11:08 |
| URI: | https://pred.uni-regensburg.de/id/eprint/44657 |
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