Vortex Density of States and Absorption in Clean Layered Superconductors

TL;DR

This paper investigates the localized vortex core states in clean layered superconductors, revealing a universal level statistics class and calculating the density of states, with implications for absorption due to Landau-Zener transitions.

Contribution

It identifies a new universal class of level statistics (circular unitary ensemble) in vortex core states of clean layered superconductors and computes the density of states under these conditions.

Findings

Universal level statistics class identified as circular unitary ensemble.

Density of states calculated for the vortex core spectrum.

Absorption from Landau-Zener transitions differs from classical isotropic models.

Abstract

We study the spectrum of the states localized in the vortex cores in the mixed state of clean layered superconductors. S-wave coupling is assumed. It is found that in a large region of parameters adjacent to the superclean case a new universal (i.e. independent of the density of impurities) class of level statistics arises. It is the circular unitary random matrix ensemble. The density of states for such conditions is calculated. The absorption resulting from the Landau-Zener transitions between these levels is different from the classical result for an isotropic three-dimensional system.