Observation of thermally activated quasiparticle interaction by ballistic electron transport and electron focusing

Electron focusing patterns originating from ballistic electron transport in single crystalline materials are observed in transmission. Spatially resol ved excitation by scanning electron microscopy and detection by a point con tact is employed for imaging. The effects of electron-phonon and electron-e lectron interactions are demonstrated for bismuth by observation of the the rmal dependence of the spatially resolved transport properties of quasipart icles in the range of 5-100 K. (C) 1999 Elsevier Science B.V. All rights re served.