Quasiparticle Density of States of Clean and Dirty s-Wave Superconductors in the Vortex State
arXiv:cond-mat/9902264 · doi:10.1143/JPSJ.68.1078
Abstract
The quasiparticle density of states (DOS) in the vortex state has been probed by specific heat measurements under magnetic fields (H) for clean and dirty s-wave superconductors, Y(Ni1-xPtx)2B2C and Nb1-xTaxSe2. We find that the quasiparticle DOS per vortex is appreciably H-dependent in the clean-limit superconductors, while it is H-independent in the dirty superconductors as expected from a conventional rigid normal electron core picture. We discuss possible origins for our observations in terms of the shrinking of the vortex core radius with increasing H.
5 pages, 4 figures, to appear in J. Phys. Soc. Jpn. Vol. 68 No. 4