Abstract
We present a theoretical study of the damping phenomenon in a device of coupled quantum dots, in the context of quantum computation. We derive the one-phonon contribution to the damping rate, based on Fermi's golden rule, for the case where the device lies in the super-Ohmic regime. The result is in agreement with that of Leggett et al derived within the noninteracting blip approximation (NIBA). Moreover, we consider the multi-phonon contribution to damping according to Würger, and estimate the temperature range for the coupled dots to operate as a qubit device. A threshold temperature T * , 18 K, is determined, above which the tunnelling time becomes longer than the damping time. © 2006 IOP Publishing Ltd.