Published in Phys. Rev. B 80, 075320 (2009).

Influence of surface states on tunneling spectra of n-type GaAs(110) surfaces

Nobuyuki Ishida,1 Kazuhisa Sueoka,1 and R. M. Feenstra2
1Graduate School of Information Science and Technology, Hokkaido University, kita-14 Nishi-9, Kita-ku, Sapporo 060-0814, Japan
2Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA


We show that surface states within the conduction band of n-type GaAs(110) surfaces play an important role in reducing the tunneling current out of an accumulation layer that forms due to an applied potential from a nearby probe tip. Numerical computation of the tunneling current combined with an electrostatic potential computation of the tip-induced band bending (TIBB) reveals that occupation of the surface states limits the TIBB, thus leading to the limitation of the accumulation. As a result, the tunneling current out of the accumulation layer is strongly suppressed, which is in quantitative agreement with the experiment.

Click here for reprint of paper, in pdf format.

Return to Home Page of Feenstra group