Magnetic field dependent zero-bias diffusive anomaly in Pb-oxide-n-InAS structures: Coexistence of 2D and 3D states

The results of experimental and theoretical studies of zero-bias anomaly (Z BA) in the Pb-oxide-n-InAs tunnel structures in magnetic field up to 6 T ar e presented. A specific feature of the structures is a coexistence of the 2 D and 3D states at the Fermi energy near the semiconductor surface. Experim entally observed magnetic field dependence of the amplitude of ZBA for diff erent orientations of the magnetic field is in agreement with the proposed theoretical model. According to this model, electrons tunnel into 2D states , and move diffusively in 2D layer, whereas the main contribution to the sc reening comes from 3D electrons. (C) 1998 Elsevier Science B.V. All rights reserved.