INFLUENCE OF NONEQUILIBRIUM PHONONS ON THE AMPLITUDE OF MAGNETOQUANTUM OSCILLATIONS IN THE POINT-CONTACT RESISTANCE

For metallic point contacts with Be and Al the magnetoquantum oscillat ions in the contact resistance have been investigated as a function of the applied voltage over the contact. For one set of point contacts t he oscillation amplitude is found to vary nonmonotonously with the app lied voltage with similarities to the point-contact spectrum of the el ectron-phonon interaction. The other part of the investigated point co ntacts shows a decrease of the oscillation amplitude with increasing b ias voltage. For the understanding of the voltage dependence of the am plitude of the point-contact magnetoresistance oscillations the influe nce of nonequilibrium phonons generated by the ballistically injected electrons will be discussed.