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Acoustically induced stark effect for excitons in intrinsic semiconductors
1Department of Physics and Astronomy, Cardiff University, Queen's Buildings, 5 The Parade, Cardiff, Wales CF24 3YB, United Kingdom.
Physical Review Letters
|October 3, 2001
Summary
We propose an acoustic Stark effect for excitons in semiconductors. Coherent acoustic phonons tune optical band gaps, altering exciton spectral shapes and enabling new optoelectronic applications.
Area of Science:
- Condensed matter physics
- Optoelectronics
- Semiconductor nanostructures
Background:
- Excitons in semiconductors are crucial for optoelectronic devices.
- Controlling exciton properties with external fields is essential for device applications.
- Acoustic waves offer a novel method for modulating semiconductor properties.
Purpose of the Study:
- To propose and theoretically investigate a novel acoustic Stark effect for excitons.
- To demonstrate tunable optical band gaps induced by acoustic pumping.
- To explore the application of this effect in semiconductor nanostructures.
Main Methods:
- Theoretical modeling of the acoustic Stark effect using an exactly solvable model.
- Parametric driving of excitons by coherent acoustic phonons.
- Probing the system with low-intensity light to observe spectral changes.
Main Results:
- A Stark effect for excitons driven by acoustic phonons is theoretically demonstrated.
- Tunable optical band gaps are induced, significantly altering exciton line shapes.
- The model is applied to GaAs, considering bulk and surface acoustic waves.
Conclusions:
- The proposed acoustic Stark effect provides a new mechanism for controlling exciton properties.
- This effect enables tunable optical band gaps in semiconductors and nanostructures.
- Potential applications in advanced optoelectronic devices and quantum information processing.