ELECTRON-ELECTRON RELAXATION IN HETEROSTRUCTURES

Stimulated by recent data for the electron-electron relaxation time me asured in two different double quantum-well systems we consider both i ntralayer and interlayer screened electron-electron interactions and i nclude a contribution beyond the simple golden-rule result. In particu lar, we find that (i) including a nongolden-rule contribution of the s ame order in the interaction always reduces the rate, (ii) as a result , our intralayer golden-rule contribution is significantly smaller tha n all published calculations, and (iii) while including interlayer sca ttering may increase the rate, it is still less than the measured rate in a wide double-quantum-well system.