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Using dark states for exciton storage in transition-metal dichalcogenides
Frank Tseng1, Ergun Simsek, Daniel Gunlycke
1National Research Council Research Associate, Washington DC 20001, USA. Naval Research Laboratory, Washington DC 20375, USA.
Journal of Physics. Condensed Matter : an Institute of Physics Journal
|December 26, 2015
Summary
We demonstrate storing excitons in dark states in transition-metal dichalcogenides. This extends exciton lifetimes, enabling potential applications in energy management and quantum information processing.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Excitons in transition-metal dichalcogenides are crucial for optoelectronic applications.
- Short exciton lifetimes currently limit their practical use.
- Optically inactive dark states offer a potential route to prolong exciton existence.
Purpose of the Study:
- To investigate the feasibility of storing excitons in dark states within monolayer transition-metal dichalcogenides.
- To explore methods for controlling transitions into and out of these dark states.
- To assess the potential for extended exciton lifetimes for technological applications.
Main Methods:
- Development of an atomistic exciton model.
- Derivation of transition matrix elements and selection rules.
- Population analysis simulating exciton dynamics with varying decay constants.
Main Results:
- Identification of specific dark states suitable for exciton storage.
- Establishment of a selection rule for transitioning excitons into and out of dark states using pulsed infrared lasers.
- Demonstration of prolonged exciton lifetimes through population dynamics simulations.
Conclusions:
- Monolayer transition-metal dichalcogenides can host excitons in long-lived dark states.
- Pulsed infrared lasers provide a viable mechanism for manipulating these excitons.
- Extended exciton lifetimes open avenues for advanced energy management and quantum information processing.
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