Magnetic-field-induced surface quantum states in organic conductors

Abstract

Analysis of the surface quantum states in quasi-two dimensional organic conductors induced by an external magnetic field is carried out within the quasi-classical approximation. In a magnetic field parallel to the surface along the y direction, these states result from the electronic transitions between the small closed orbits in the vicinity of the Fermi surface which are extremal cross-sections of the Fermi surface by the plane ε(p)=εF, py=const. The magnetic surface levels are calculated for the electrons moving on skipping orbits near the conductor's surface with a centre of rotation outside and inside the conductor, respectively. The former are the shallow skipping electrons as their motion is very close to the surface so they are practically sliding along the surface and the latter have trajectories that span deeper in the conductor's skin layer and therefore are more affected by the bulk electrons. The features of their corresponding magnetic surface levels are revealed and differences in the unperturbed energy spectrum of both type of skipping electrons are addressed. The magnetic field values at which the resonance peaks in the oscillation spectrum, associated with the surface resonance transitions, should be observed are obtained. Further theoretical and experimental studies on the surface states and related to them effects might give new important and more precise information on the properties, Fermi surface parameters and transport processes in organic conductors.