Europhys. Lett.
Volume 62, Number 5, June 2003
Page(s) 712 - 718
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 May 2003
DOI: 10.1209/epl/i2003-00431-5
Europhys. Lett., 62 (5) , pp. 712-718 (2003)

Spin blockade in ground-state resonance of a quantum dot

A. K. Hüttel1, H. Qin1, A. W. Holleitner1, R. H. Blick1, K. Neumaier2, D. Weinmann3, K. Eberl4 and J. P. Kotthaus1

1  Center for NanoScience and Sektion Physik, Ludwig-Maximilians-Universität Ge schwister-Scholl-Platz 1, 80539 München, Germany
2  Walther-Meissner-Institut für Tieftemperaturforschung Walther-Meissner-Straße 8, 85748 Garching, Germany
3  Institut de Physique et Chimie des Matériaux de Strasbourg UMR 7504 (CNRS-ULP) - 23 rue du Loess, 67037 Strasbourg, France
4  Max-Planck-Institut für Festkörperforschung Heisenbergstraße 1, 70569 Stuttgart, Germany

(Received 16 September 2002; accepted in final form 19 March 2003)

We present measurements on spin blockade in a laterally integrated quantum dot. The dot is tuned into the regime of strong Coulomb blockade, confining $\sim 50$ electrons. At certain electronic states we find an additional mechanism suppressing electron transport. This we identify as spin blockade at zero bias, possibly accompanied by a change in orbital momentum in subsequent dot ground states. We support this by probing the bias, magnetic field and temperature dependence of the transport spectrum. Weak violation of the blockade is modelled by detailed calculations of non-linear transport taking into account forbidden transitions.

73.21.La - Quantum dots.
85.35.Gv - Single-electron devices.
72.25.Rb - Spin relaxation and scattering.

© EDP Sciences 2003