ELASTIC-SCATTERING AND ABSORPTION OF SURFACE ACOUSTIC-WAVES BY A QUANTUM-DOT

The piezoelectric interaction of a surface acoustic wave (SAW) with a quantum dot is studied. Electron-electron interactions are accounted f or by solving the screening problem in real space. The absorption and the scattering cross sections for SAW's as a function of the area of t he dot, A, the sound wave vector, q, and the diffusion coefficient, D, of the electrons are calculated analytically in ail cases where the q uantities q(2)A and A omega/D are larger or smaller than unity; omega is the SAW frequency. Numerical results cover the intermediate regimes . Based on the calculation of the weak localization corrections to the cross sections it is argued that scattering and absorption of sound a s noninvasive probes mag. be advantageous in comparison to transport e xperiments for the investigation of small electronic systems, because for the former the phase coherence is enhanced as the system size shri nks.