Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.46: Poster

Montag, 8. März 2004, 16:30–19:00, Poster A

Interactions and Integer Quantum Hall Fluctuations — •Christoph Sohrmann und Rudolf A. Römer — Department of Physcis and Centre for Scientific Computing, University of Warwick, Coventry CV4 7AL, UK

The integer quantum Hall effect appears to be well-describable by models of non-interacting electrons in a strong magnetic field. Results seem in very good agreement with experiments. Even mesoscopic conductance fluctuations can be shown do have similarly broad distributions as in the experimental situation [1]. However, in 1999 Cobden et al. [2] reported strong evidence for a profound effect of the electron-electron interactions in the integer regime. The authors investigated sample specific conductance fluctuations in mesoscopic MOSFET devices. In contrast to the random behaviour of the conductance as a function of one parameter — such as, e.g., the magnetic field — they found regular patterns for the conductance when viewed as a function of the two parameters magnetic field and gate voltage. Using a numerical approach, we are studying these fluctuations within a Hartree-Fock formulation and check whether the interaction can indeed lead to the observed behavior.