Superconductor vortex lines

In superconductors of the second kind at T< in a mixed state (in a magnetic field between Hei and H 2, where is the lower and H 2 the upper critical field) a new effect in the thermal conductivity is possible phonon and electron scattering by Abrikosov vortex lines penetrating the superconductor (Red ko and Chakalski 1987). 

Only a weak attractive interaction occurs between the pancake vortices of different layers, the strength of which depends on the magnetic field and the temperature. Therefore the pancake vortices are much more flexible than the continuous, relatively rigid vortex lines in conventional superconductors. 

Collective modes of vortex lines in type II superconductors (with... 

X. Vortex lines in superconductors Rapport a la 9eme Conference de Physique des Basses Temperatures (Columbus, Ohio 1964). 

Bound fermion state on a vortex line in a type II superconductor (with C, Caroli and J. Matricon), Phvs. Lett., J, 307 (1965). 

The nonnal threads are called vortices or fluxoids. The currents act so as to repel each other, so that the flux lines form an ordered structure called a fluxon lattice, flux lattice or vortex lattice. At the core of each flux vortex the material is effectively normal, but is surrounded by a region of superconductor. 

The low temperature dependence of the specific heat is apparently described by a power law behaviour Q T" with n between 2 and 3 (Hilscher and Michor, 1999). Thermal conductivity Kxx (Boaknin et al., 2001) clearly exhibits T-linear behaviour for T < Tc suggesting the presence of nodal lines or second order node points as introduced below which would be compatible with n = 2 for the specific heat. Furthermore the investigation of field (and field-angle) dependence of Cs (T, H) and Kij T, H) (/, j =x,y,z) is a powerful method to obtain information on the quasiparticle spectrum and hence on the anisotropy properties of the gap function (sect. 2). In a conventional superconductor with isotropic gap the quasiparticles at low temperature are confined to the vortex core where they form closely spaced bound states with an energy difference much smaller than kT. Therefore, they can be taken as a... 

Schilling et al. (1993) observed a cross-over in the irreversibility line measured with // II c on single-crystal specimens of a Bi2Sr2CaCu20g superconductor Irom a parabolic temperature dependence, //=/fo(l - T /T c). near to an exponential dependence, exp(const/7 ), at larger H and TIT < 0.5. They argued that the two regimes reflect a cross-over from essentially three-dimensional (3D) vortex fluctuations near Tc to quasi-two-dimensional (2D) vortex fluctuations for H >Ha ols y and low temperatures, where s is the interlayer distance, y=Ac/Aab is the anisotropy parameter, and 0o is the magnetic flux quantum. 

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