The energy level spacing distribution of a tight-binding Hamiltonian is monitored across the mobility edge for a fixed disorder strength. Any mixing of extended and localized levels is avoided in the configurational averages, thus approaching the critical point very closely and with high energy resolution. By finite-size scaling the method is shown to provide a very accurate estimate of the mobility edge and of the critical exponent for a cubic lattice with Lorentzian distributed diagonal disorder. Since no averaging in wide energy windows is required, the method appears as a powerful tool for locating the mobility edges in more complex models of real physical systems.

Mobility edge and level statistics of random tight-binding Hamiltonians

SIRINGO, Fabio;PICCITTO, Giovanni
1998-01-01

Abstract

The energy level spacing distribution of a tight-binding Hamiltonian is monitored across the mobility edge for a fixed disorder strength. Any mixing of extended and localized levels is avoided in the configurational averages, thus approaching the critical point very closely and with high energy resolution. By finite-size scaling the method is shown to provide a very accurate estimate of the mobility edge and of the critical exponent for a cubic lattice with Lorentzian distributed diagonal disorder. Since no averaging in wide energy windows is required, the method appears as a powerful tool for locating the mobility edges in more complex models of real physical systems.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/34122
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