ar X iv : c on d - m at / 9 30 10 06 v 1 7 J an 1 99 3 Electronic structure of superconducting Ba 6 C 60 Steven

ar X iv : c on d - m at / 9 30 70 06 v 1 5 J ul 1 99 3 Flux flow dissipation in superconductors with short coherence length

In superconductors where the coherence length is comparable to the Fermi wavelength , the electronic levels within a vortex core are quantized, and separated by energies of the order of the superconducting gap. The absence of a continuum modifies significantly the energy dissipation due to the motion of vortices. At zero temperature , dissipation is suppressed, and the system shows non ohmic be...

ar X iv : c on d - m at / 9 70 30 28 v 1 3 M ar 1 99 7 In - plane optical response of Bi 2 Sr 2 CuO 6

We report on infrared reflectivity measurements of the ab-plane response of superconducting Bi2Sr2CuO6 single crystals. The frequency dependent conductivity has a maximum near 500 cm at room temperature, which shifts to lower frequency and merges with a Drude peak below 100 K. We attribute the unusual behavior of the mid-infrared conductivity to low frequency transitions between electronic band...

ar X iv : c on d - m at / 9 60 30 39 v 1 6 M ar 1 99 6 Theory for Spin - Polarized Oscillations in Nonlinear Magneto - Optics due to Quantum Well States

Using an electronic tight-binding theory we calculate the nonlinear magneto-optical response from an x-Cu/1Fe/Cu(001) film as a function of frequency and Cu overlayer thickness (x=3. . .25). We find very strong spinpolarized quantum well oscillations in the nonlinear magneto-optical Kerr effect (NOLIMOKE). These are enhanced by the large density of Fe d states close to the Fermi level acting as...

ar X iv : c on d - m at / 9 40 30 13 v 1 3 M ar 1 99 4 Nesting Mechanism for d - symmetry Superconductors ∗

A nested Fermi surface with nearly parallel orbit segments is found to yield a singlet d–wave superconducting state at high temperatures for a restricted range of the on–site Coulomb repulsion that avoids the competing spin density wave instability. The computed superconducting transition temperature drops dramatically as the nesting vector is decreased, in accord with recent photo–emission dat...

ar X iv : c on d - m at / 9 60 31 90 v 1 2 9 M ar 1 99 6 The Four - Dimensional XY Spin Glass