Münster 1999 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 38: Quantenpunkte und Quantendr
ähte: Theorie
HL 38.2: Vortrag
Donnerstag, 25. März 1999, 17:45–18:00, H4
Two interacting particles in a two dimensional random environment — •R. A. Römer1, M. Leadbeater2, and M. Schreiber1 — 1Institut für Physik, Technische Universität, D-09107 Chemnitz — 2Dipartimento di Fisica, Universita di Roma Tre, I-00146 Roma, Italy
Much numerical evidence has been collected as of today which shows
that repulsive electron-electron interaction can lead to the formation
of particle pairs in a one-dimensional random energy landscape [1,2].
The localization length of these pair states is finite, but larger
than the localization length of the individual particles. Very
recently, it has been argued, based on numerical results for small
system sizes [3], that the influence of interaction can even lead to
the formation of pairs which are extended in the thermodynamic limit.
Here we present results of a numerical investigation of the 2D problem
using the decimation method of Ref. [2]. We analyse various possible
definitions of the localization length and apply finite-size scaling
in order to study the existence of the postulated interaction-induced
metal-insulator transition.
[1] D. L. Shepelyansky, Phys. Rev. Lett. 73, 2607 (1994).
M. Leadbeater, R. A. Römer, and M. Schreiber, accepted for publication in Eur. Phys. J. B, (1998, cond-mat/9806255).
M. Ortuño and E. Cuevas, preprint (1998, cond-mat/9808104).