Planar acoustomagnetoelectric effect in three-dimensional Dirac materials

Abstract

Using the Boltzmann equation techniques, we develop a theory of the planar acoustomagnetoelectric (AME) effect in three-dimensional (3D) gapless Dirac materials with a linear (massless) dispersion law of conduction electrons. The effect arises if the magnetic field [Formula: see text] applied to the sample makes an angle [Formula: see text], [Formula: see text] with the wavevector [Formula: see text] of the acoustic wave and consists in the appearance of a dc electric field [Formula: see text] directed perpendicular to the wavevector [Formula: see text], with all three vectors [Formula: see text], [Formula: see text], and [Formula: see text] lying in the same plane. We study this effect in the quantum regime (the electron mean free path [Formula: see text] is large compared to the wavelength [Formula: see text]), where it occurs as a result of the momentum transfer from an excited acoustic wave, considered a flow of individual acoustic quanta, to conduction electrons subjected to the magnetic field. Our theory predicts that for the 3D Dirac material [Formula: see text] exposed to a strong, but non-quantizing magnetic field [Formula: see text] kOe and an acoustic wave with a frequency of 10 GHz and an intensity of 2 kW/[Formula: see text], the AME field [Formula: see text] with its specific angular dependence ([Formula: see text]) can reach values of the order of 0.01 V/cm at room temperature, which can be readily measured in the experiment.