Angular resolved phonon emission from excited quantum dots

We calculate the angular emission characteristics of phonons from parabolic confined quantum dots containing a single or two interacting electrons. The emission spectra are shown to be generally characterized by a narrow polar angle giving a phonon propagation direction explicitly characterized by the energy difference of the transition. In addition, the phonon emission spectra contain a given number of azimuthally oriented lobes which reflect the quantum structure of the initial excited state. This implies that measurements of angular resolved phonon emission spectra can give detailed information on the electronic charge distribution and energy spectra of excited quantum states. When such a structure is known, a large-scale ordering of identical quantum dots with respect to the emission angles may realize phonon amplification by stimulated emission. (paper)