Magnetic-field-dependent Zero-bias Diffusive Anomaly in Pb oxide– n-InAs Structures: Coexistence of Two- and Three-dimensional States

The results of experimental and theoretical studies of zero-bias anomaly (ZBA) in the Pb-oxide-(Formula presented)-InAs tunnel structures in magnetic field up to 6 T are presented. A specific feature of the structures is a coexistence of the two-dimensional (2D) and 3D states at the Fermi energy near the semiconductor surface. The dependence of the measured ZBA amplitude on the strength and orientation of the applied magnetic field is in agreement with the proposed theoretical model. According to this model, electrons tunnel into 2D states, and move diffusively in the 2D layer, whereas the main contribution to the screening comes from 3D electrons. © 1999 The American Physical Society.We would like to thank J. Kyriakidis for a critical reading of the manuscript and for very helpful discussions. This work was supported in part by the RFBR through Grants No. 97-02-16168 and 98-02-17286, the Russian Program ‘‘Physics of Solid State Nanostructures’’ through Grant No. 97-1091, and the Program ‘‘University of Russia’’ through Grant No. 420 at the Institute of Physics and Applied Mathematics, and by the Swiss National Science Foundation at the University of Basel (E.V.S.)

Magnetic-field-dependent zero-bias diffusive anomaly in Pb oxide-n-InAs structures: Coexistence of two- and three-dimensional states

The results of experimental and theoretical studies of zero-bias anomaly (ZBA) in the Pb-oxide-n-InAs tunnel structures in magnetic field up to 6T are presented. A specific feature of the structures is a coexistence of the 2D and 3D states at the Fermi energy near the semiconductor surface. The dependence of the measured ZBA amplitude on the strength and orientation of the applied magnetic field is in agreement with the proposed theoretical model. According to this model, electrons tunnel into 2D states, and move diffusively in the 2D layer, whereas the main contribution to the screening comes from 3D electrons.Comment: 8 double-column pages, REVTeX, 9 eps figures embedded with epsf, published versio