Regensburg 1998 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 21: Postersitzung III: Spin-Peierls-Systeme, Metall-Isolator-Übergang, Lokalisierung; SL: Theorie; Quantenflüssigkeiten und -kristalle; Amorphe Materialien, Tunnelsysteme; Borcarbide, Fullerene, konventionelle SL; SL dünner Filme; Experimentiertechniken
TT 21.14: Poster
Donnerstag, 26. März 1998, 15:00–18:30, D
Asymptotics of Universal Probability of Neighboring Level Spacings at the Anderson Transition — •I.Kh. Zharekeshev and B. Kramer — I. Institut für Theoretische Physik, Jungiusstraße 9, D-20355 Hamburg
The nearest-neighbor level spacing distribution is numerically investigated by directly diagonalizing disordered Anderson Hamiltonians for systems of sizes up to 100 × 100 × 100 lattice sites [1]. The scaling behavior of the level statistics is examined for large spacings near the delocalization-localization transition and the correlation length exponent is determined. At the critical point we find the universal asymptotic form of the cumulative probability of neighboring spacings I(s) ∝ exp(−Ac sα) with a constant Ac ≈ 1.9 and α = 1.0 ± 0.1, which is independent of fundamental symmetry [2]. By using high-precision calculations we propose a new interpolation formula to describe critical level statistics [1].
[1] I. Kh. Zharekeshev, B. Kramer, Phys. Rev. Lett. 79, 717 (1997)
[2] M. Batsch, L. Schweitzer, I. Kh. Zharekeshev, B. Kramer, Phys. Rev. Lett. 77, 1552 (1996)