ELECTRON-ELECTRON SCATTERING IN METAL-INSULATOR-METAL SANDWICHES

We have studied weak localization and electron-electron interaction effects in samples consisting of two thin metal films separated by an insulating layer of SiO. When the SiO thickness was less than about 200 angstrom, the electron-electron scattering rate was enhanced with respect to that found in isolated, i.e., well-separated, films. This suggests that in the sandwich structures, electrons in one metal film are able to ''communicate'' with, i.e., scatter from, electrons in the other film across distances of order 200 angstrom, and that this process enhances the phase-breaking rate.