Europhys. Lett.
Volume 66, Number 5, June 2004
Page(s) 701 - 707
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 May 2004
Europhys. Lett., 66 (5) , pp. 701-707 (2004)
DOI: 10.1209/epl/i2003-10250-8

Re-entrant pinning of Wigner molecules in a magnetic field due to a Coulomb impurity

B. Szafran1, 2 and F. M. Peeters1

1  Departement Natuurkunde, Universiteit Antwerpen (Campus Drie Eiken) B-2610 Antwerpen, Belgium
2  Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology - al. Mickiewicza 30, 30-059 Kraków, Poland

(Received 5 December 2003; accepted in final form 29 March 2004)

Pinning of magnetic-field-induced Wigner molecules (WMs) confined in parabolic two-dimensional quantum dots by a charged defect is studied by an exact diagonalization approach. We found a re-entrant pinning of the WMs as a function of the magnetic field, a magnetic-field-induced re-orientation of the WMs and a qualitatively different pinning behaviour in the presence of a positive and negative Coulomb impurity.

73.21.La - Quantum dots.
73.20.Qt - Electron solids.

© EDP Sciences 2004