Fictitious forces and electronic energy relaxation in nanocrystals

It is well known that a localized electronic impurity state couples to the vibrational modes of an insulating nanoparticle through the ordinary electron}phonon interaction, enhanced by the e!ects of quantum con"nement. In this paper we show that an electron can also interact with the translational degrees of freedom of a nanoparticle. The form of the coupling is dictated by Einstein's equivalence principle and is independent of the ordinary electron}phonon interaction. We calculate the rate of electronic energy relaxation provided by this mechanism and establish its experimental observability. ( 1999 Elsevier Science B.V. All rights reserved.