We present experimental results demonstrating that the generation of terahertz acoustic waves using femtosecond laser pulses is possible in quantum dots (QDs). Very short and strong pulses are emitted from a buried QD layer and detected at the sample surface. By tuning the laser wavelength we can detect, at room temperature, frequencies above 1 THz using a photoelastic mechanism. A theoretical model supports such a capability and shows that around an interband transition the bandwidth of the photoelastic detection can be greatly improved. These results suggest that QD can be an ultrahigh-frequency acoustic transducer needed for nanoscale acoustics.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 19 Mar 2010|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics