Experimental study of quantum structures in solids

The object of the experiment is to measure electron binding energy spectra in solids at a series of selected bound electron momenta. The present apparatus is based on developments in atomic and molecular spectroscopy and uses a 10 keY electron beam incident on a thin (80 A) amorphous carbon film. The exit electrons in the (e,2e) reaction are studied in a symmetric coplanar geometry using hemispherical analysers and position-sensitive detectors. The resultant coincidence count rate is proportional to the probability of finding a target electron with a given binding energy and momentum. Data were obtained with binding energies from 0 to 40 eV with momentum as parameter. Contributions from the rr and u bands are clearly demonstrated. Future investigations in a new experimental system will be devoted to single crystals of metals, semiconductors and macro-molecules.