Europhys. Lett.
Volume 71, Number 4, August 2005
Page(s) 658 - 664
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 13 July 2005
Europhys. Lett., 71 (4), pp. 658-664 (2005)
DOI: 10.1209/epl/i2005-10115-2

Spontaneous current generation in gated nanostructures

D. W. Horsell1, A. K. Savchenko1, Y. M. Galperin2, 3, 4, V. I. Kozub3, 4, V. M. Vinokur4 and D. A. Ritchie5

1  School of Physics, University of Exeter - Exeter, EX4 4QL, UK
2  Department of Physics, University of Oslo - PO Box 1048 Blindern 0316 Oslo, Norway
3  A. F. Ioffe Physico-Technical Institute of Russian Academy of Sciences 194021 St. Petersburg, Russia
4  Argonne National Laboratory - 9700 S. Cass av., Argonne, IL 60439, USA
5  Cavendish Laboratory, University of Cambridge - Cambridge, CB3 0HE, UK

received 11 March 2005; accepted in final form 16 June 2005
published online 13 July 2005

We have observed an unusual dc current spontaneously generated in the conducting channel of a short-gated $\chem{GaAs}$ transistor. The magnitude and direction of this current critically depend upon the voltage applied to the gate. We propose that it is initiated by the injection of hot electrons from the gate that relax via phonon emission. The phonons then excite secondary electrons from asymmetrically distributed impurities in the channel, which leads to the observed current.

72.20.-i - Conductivity phenomena in semiconductors and insulators.
72.90.+y - Other topics in electronic transport in condensed matter.

© EDP Sciences 2005