Generation of nonequilibrium phonons in Bi in a quantizing magnetic field

Abstract

The voltage across a Bi single crystal in the [E×H] direction (transverse voltage E⊥) is investigated in strong crossed electric E and magnetic H fields under phonon generation conditions. Information on electron acousto-emf Eea of bismuth, forming segments with a negative differential conductivity on current–voltage characteristics j vs. E⊥, is obtained. Acousto-emf is measured as the absolute value of the difference in transverse voltage before and after the transition of the sample to the phonon generation mode. It is found that the dependence of acousto-emf on quantizing magnetic field is nonmonotonic. This is associated with oscillations in the electron–phonon generation rate ∂Nq/∂t in a magnetic field, i.e., with oscillations of the phonon–electron collision frequency τpe−1.