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Safi R. Bahcall

Publications and source records attributed to Safi R. Bahcall.

4 recordsLinked to original sources
arXiv1997

The Cooperon and the Random Matrix Model for Type-II Superconductors

We derive the connection between the Cooperon problem in weak localization theory and the random matrix description of type-II superconductors. As magnetic field and disorder increase, an extreme type-II superconductor crosses over from a state in which the low energy quasiparticles are primarily localized and the density of states is determined by the electronic structure of individual vortices, to a `chaotic' state, in which quasiparticles are primarily extended and the density of states is determined by the random matrix description.

cond-mat↗
arXiv1996

Random Matrix Model for Superconductors in a Magnetic Field

We introduce a random matrix ensemble for bulk type-II superconductors in the mixed state and determine the single-particle excitation spectrum using random matrix theory. The results are compared with planar tunnel junction experiments in PbBi thin films. More low energy states appear than in the Abrikosov-Gor'kov-Maki or Ginzburg-Landau descriptions, consistent with observations.

cond-mat.supr-con↗
arXiv1996

Non-perturbative Effects Near the Upper Critical Field in Type-II Superconductors

The properties of a conventional type-II superconductor near the upper critical field are usually calculated using a perturbative expansion in the strength of the order parameter. Here we show that perturbation theory breaks down near the upper critical field and that this breakdown leads to unusual behavior near the phase transition.

cond-mat↗