LIFETIME OF 2-DIMENSIONAL ELECTRONS MEASURED BY TUNNELING SPECTROSCOPY

For electrons tunneling between parallel two-dimensional electron syst ems, conservation of inplane momentum produces sharply resonant curren t-voltage characteristics and provides a uniquely sensitive probe of t he underlying electronic spectral functions. We report here the applic ation of this technique to accurate measurements of the temperature de pendence of the electron-electron scattering rate in clean two-dimensi onal systems. Our results are in qualitative agreement with existing c alculations.