ANISOTROPY OF ZERO-BIAS DIFFUSIVE ANOMALIES FOR DIFFERENT ORIENTATIONS OF AN EXTERNAL MAGNETIC-FIELD

We consider the influence of the electron-electron interaction on the nonlinearity of the current-voltage characteristic of the tunnel junct ion at low bias (diffusive anomaly) in the presence of the classical m agnetic field. We present the theory of a phenomenon which manifests i tself in the strong anisotropy of a diffusive anomaly for different or ientations 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 characte ristic does not depend on the value of the magnetic field.