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Exciton Steering via Potential Landscape Engineered by Excited Electron-Hole Phase Transition
Yiling Yu1, Yan Xu1, Volodymyr Turkowski2
1Wuhan University, Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan 430072, China.
Physical Review Letters
|July 7, 2026
Summary
Researchers demonstrate all-optical steering of intralayer excitons in monolayer MoS2 using phase transitions. This method controls exciton and free carrier transport, enabling new optical devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Controlling exciton transport, particularly intralayer excitons, is difficult due to a lack of efficient driving mechanisms.
- This limitation hinders the development of practical excitonic devices.
Purpose of the Study:
- To demonstrate all-optical steering of intralayer excitons in monolayer MoS2.
- To investigate the role of optically driven excitonic phase transitions in controlling photocarrier transport.
Main Methods:
- Utilized spatial emission and microscopic theory.
- Employed drift-diffusion modeling to analyze exciton and carrier behavior.
- Investigated optically driven excitonic phase transitions and the exciton-Mott transition.
Main Results:
- Spatial screening from high-excitation phase transitions creates exciton binding energy gradients.
- These gradients drive excitons towards higher binding energy regions.
- Engineered screening profiles create an energy landscape that directs excitons and free carriers in opposite directions (counterflow).
Conclusions:
- Excitons in 2D semiconductors act as cohesive quasiparticles, distinct from free carriers moving along band edges.
- All-optical control of photocarrier transport is achievable through engineered energy landscapes.
- This work offers a new approach for reconfigurable excitonic interconnects and quantum optical devices.
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