Electronic structure of unidirectional superlattices in crossed electric and magnetic fields and related terahertz oscillations

摘要

We have studied Bloch electrons in a perfect unidirectional superlattice subject to crossed electric and magnetic fields, where the magnetic field is oriented "in plane," i.e., parallel to the sample plane. Two orientations of the electric field are considered. It is shown that the magnetic field suppresses the intersubband tunneling of the Zener type, but does not change the frequency of Bloch oscillations, if the electric field is oriented perpendicularly to both the sample plane and the magnetic field. The electric field applied in plane (but perpendicular to the magnetic field) yields the steplike electron energy spectrum, corresponding to the magnetic-field-tunable oscillations alternative to the Bloch ones.