Thermoelectric phenomena in layered conductors near the Lifshitz electron topological transition

Abstract

This is a theoretical study of the response of an electron system to nonuniform heating of layered conductors with a quasi-two dimensional charge carrier energy spectrum near the Lifshitz electron topological transition when external interactions with the conductor, such as pressure, cause a change in the connectivity of the Fermi surface. With a variety of dispersion relations for the conduction electrons as examples, it is shown that there is a great variety of electronic topological transitions in layered conductors, which are accompanied by unusual magnetic field dependences of the kinetic coefficients. The migration of conduction electrons over different cavities (sheets) of the Fermi surface owing to magnetic breakdown is analyzed for close proximity of individual cavities of the Fermi surface. The dependence of the thermoelectric coefficients on the magnitude and orientation of strong magnetic fields B, such that the cyclotron frequency ωc is much higher than the collision frequency 1/τ of the conduction electrons, is calculated. An experimental study of these effects yields important information on the energy spectrum of the charge carriers.