We report on the experimental observation by scanning tunneling microscopy at low temperature of ring-like features that appear around Co metal clusters deposited on a clean (110) oriented surface of cleaved p-type InAs crystals. These features are visible in spectroscopic images within a certain range of negative tunneling bias voltages due to the presence of a negative differential conductance in the current-voltage dependence. A theoretical model is introduced, which takes into account non-equilibrium effects in the small tunneling junction area. In the framework of this model the appearance of the ring-like features is explained in terms of interference effects between electrons tunneling directly and indirectly (via a Co island) between the tip and the InAs surface.
@article{arxiv.0712.2012,
title = {Low-temperature scanning tunneling microscopy of ring-like surface electronic structures around Co islands on InAs(110) surfaces},
author = {D. A. Muzychenko and K. Schouteden and S. V. Savinov and N. S. Maslova and V. I. Panov and C. Van Haesendonck},
journal= {arXiv preprint arXiv:0712.2012},
year = {2012}
}