Geometrical exponents in the integer quantum Hall effect
I. Bratberg; A. Hansen; E. H. Hauge; I. Bratberg; Institutt for Fysikk, Norges Teknisk-naturvitenskapelige Universitet, N-7034 Trondheim, Norway; A. Hansen; Institutt for Fysikk, Norges Teknisk-naturvitenskapelige Universitet, N-7034 Trondheim, Norway; E. H. Hauge; Institutt for Fysikk, Norges Teknisk-naturvitenskapelige Universitet, N-7034 Trondheim, Norway
Журнал:
EPL (Europhysics Letters)
Дата:
1997-01-01
Аннотация:
We point out that the extended Chalker-Coddington model in the “classical” limit, i.e. the limit of large disorder, shows crossover to the so-called “smart kinetic walks”. The reason why this limit has previously been identified with ordinary percolation is, presumably, that the localization length exponents ν coincide for the two problems. Other exponents, like the fractal dimension D, differ. This gives an opportunity to test the consistency of the semiclassical picture of the localization-delocalization transitions in the integer quantum Hall effect. We calculate numerically, using the extended Chalker-Coddington model, two exponents τ and D that characterize critical properties of the geometry of the wave function at these transitions. We find that the exponents, within our precision, are equal to those of two-dimensional percolation, as predicted by the semiclassical picture.
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