Absorption of surface acoustic-waves by quantum dots: discrete spectrum limit

Abstract

The absorption of surface acoustic waves (SAW&#39;s) by an array of quantum dots in which the mean level spacing Delta is larger than the sound frequency omega, the temperature T, and the phase breaking rate tau^{-1}_phi is considered. The direct and the intra-level (Debye) contributions to the SAW attenuation coefficient Gamma are evaluated, and it is shown that the sensitivity to weak magnetic fields and spin-orbit scattering (``weak localization effects&#39;&#39;) is dramatically enhanced as compared to the case of a continuous spectrum, Delta < tau^{-1}_phi. It is argued that the non-invasive measurement of Gamma represents a new tool for the investigation of the temperature dependence of the energy relaxation rate, tau^{-1}_epsilon, and the phase breaking rate, tau^{-1}_phi$, of isolated electronic systems.