Bauer, Jonas M. and Chen, Lijue and Wilhelm, Philipp and Watanabe, Kenji and Taniguchi, Takashi and Bange, Sebastian and Lupton, John M. and Lin, Kai-Qiang (2022) Excitonic resonances control the temporal dynamics of nonlinear optical wave mixing in monolayer semiconductors. NATURE PHOTONICS, 16 (11). pp. 777-783. ISSN 1749-4885, 1749-4893
Full text not available from this repository. (Request a copy)Abstract
Researchers show that resonant coupling of light pulses with excitonic transitions affects the optimal time difference between pulses for sum-frequency generation and four-wave mixing in monolayer WSe2. Monolayer semiconductors are an emerging platform for strong nonlinear light-matter interactions that are enhanced by the giant oscillator strength of tightly bound excitons. Little attention has been paid to the impact of excitonic resonances on the temporal dynamics of such nonlinearities, since harmonic generation and optical wave mixing are generally considered instantaneous processes. We find that a significant time difference, ranging from -40 to +120 fs, is necessary between two light pulses for optimal sum-frequency generation (SFG) and four-wave mixing (FWM) to occur from monolayer WSe2 when one of the pulses is in resonance with an excitonic transition. These resonances involve both band-edge A excitons and high-lying excitons that comprise electrons from conduction bands far above the bandgap. Numerical simulations in the density-matrix formalism rationalize the distinct dynamics of SFG and FWM. The interpulse delays for maximal SFG and FWM are governed primarily by the lifetime of the one-photon and two-photon resonant states, respectively. The method therefore offers an unconventional probe of the dynamics of excitonic states accessible with either one-photon or two-photon transitions. Remarkably, the longest delay times occur at the lowest excitation powers, indicating a strong nonlinearity that offers exploration potential for excitonic quantum nonlinear optics.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | QUANTUM; PHOTON |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Lupton > Group John Lupton |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 08 Feb 2024 06:47 |
| Last Modified: | 08 Feb 2024 06:47 |
| URI: | https://pred.uni-regensburg.de/id/eprint/57379 |
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