Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 47: Transport in high magnetic field/quantum-Hall-effect

HL 47.6: Vortrag

Donnerstag, 29. März 2007, 17:00–17:15, H14

Compressibility stripes for mesoscopic quantum Hall samples — •Christoph Sohrmann and Rudolf A. Römer — University of Warwick, Gibbet Hill Road, Coventry CV47AL, UK

We numerically investigate the interplay of disorder and electron-electron interactions in the integer quantum Hall effect. In particular, we focus on the behaviour of the electronic compressibility as a function of magnetic field and electron density. We find manifestations of non-linear screening and charging effects around integer filling factors, consistent with recent imaging experiments. Our calculations exhibit g-factor enhancement as well as strong overscreening in the centre of the Landau bands. Even though the critical behaviour appears mostly unaffected by interactions, important implications for the phase diagram arise. Our results are in very good agreement with the experimental findings and strongly support the relevance of electron-electron interactions for understanding integer quantum Hall physics.