Nonuniversal Corrections to the Level Curvature Distribution beyond Random Matrix Theory
Abstract
The level curvature distribution function is studied beyond the random matrix theory for the case of T-breaking perturbations over the orthogonal ensemble. The leading correction to the shape of the level curvature distribution is calculated using the nonlinear sigma model. The sign of the correction depends on the presence or absence of the global gauge invariance and is different for perturbations caused by a constant vector potential and by a random magnetic field. The Thouless conjecture of proportionality between the dimensionless conductance g¯ and the mean level curvature <\|K\|> is shown to break down in 1/g¯2 order.
- Publication:
-
Physical Review Letters
- Pub Date:
- January 1997
- DOI:
- 10.1103/PhysRevLett.78.701
- arXiv:
- arXiv:cond-mat/9609106
- Bibcode:
- 1997PhRvL..78..701Y
- Keywords:
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- Condensed Matter
- E-Print:
- 4 pages, Latex