MEASURING ELECTRON-ELECTRON SCATTERING RATES THROUGH MUTUAL FRICTION

Electron-electron (e-e) interactions have been probed using a new meas urement technique which provides direct determination of e-e scatterin g rates. The technique measures the voltage induced in one two-dimensi onal electron gas (2DEG) when a current is driven through a second, pa rallel, 2DEG. Measurements with closely spaced layers confirm the impo rtance of Coulomb scattering in the interlayer e-e interaction. For la rge layer spacings, however, Coulomb scattering diminishes rapidly and a second mechanism dominates. Measurements indicate that the strong i nterlayer interactions in this regime are due to the exchange of virtu al phonons between the electron systems.