Anisotropy of zero-bias diffusive anomalies for different orientations of an external magnetic field

TL;DR

This paper investigates how electron-electron interactions cause anisotropic effects in the nonlinear current-voltage behavior of tunnel junctions under magnetic fields, revealing a universal magnetic field dependence related to field orientation.

Contribution

It introduces a theoretical framework describing the anisotropic diffusive anomaly in tunnel junctions influenced by magnetic field orientation.

Findings

Diffusive anomaly exhibits strong anisotropy depending on magnetic field orientation.

Nonlinear conductance depends only on the magnetic field component perpendicular to the interface.

When magnetic field is parallel to the interface, the I-V characteristic is unaffected by the field.

Abstract

We consider the influence of the electron-electron interaction on the nonlinearity of the current-voltage characteristic of the tunnel junction at low bias (diffusive anomaly) in the presence of the classical magnetic field. We present the theory of a new phenomenon which manifests itself in the strong anisotropy of a diffusive anomaly for different orientations of the magnetic field with respect to the interface of the tunnel junction. The nonlinear differential tunneling conductance has a universal magnetic field dependence, so that only the magnetic field component perpendicular to the interface is involved. In particular, when the magnetic field is parallel to the interface, the I-V characteristic does not depend on the value of the magnetic field.