Document
Anisotropy; Crystal lattices; Electric conductivity; Electric currents; Magnetic field effects; Mathematical models; Melting; Order disorder transitions; Quantum theory; Statistical mechanics; Thermodynamics; Critical current density ratio; Ginzburg number; Magnetic field strength; Planar coherence length; Planar normal resistivity; Quantum fluctuations; Quantum resistance; Thermal fluctuations; Vortex lattice; High temperature superconductors
The special material parameters of the oxide superconductors lead to a dramatic increase of the importance of thermal and quantum fluctuations. The latter can be quantified by the Ginzburg number Gi = [Tc/ H2c(0)ε{lunate}ξ3(0)]2/2 and the quantum resistance Qu = (e2/ h {combining short stroke overlay}) [ρ{variant}N/ ε{lunate}ξ(0)], where Hc(0), ξ(0), and ρ{variant}N denote the thermodynamic critical field, the planar coherence length (both linearly extrapolated to zero), and the planar normal resistivity. ε{lunate}2 = m/ M < 1 is the anisotropy parameter. In the high Tc's (specifically for YBCO) we have Gi ≅ 10-2 and Qu ≅ 1 and thus these parameters are by orders of magnitude larger than in conventional low-Tc superconductors. The large fluctuations lead to the melting of the vortex lattice well below the upper critical field line. The inclusion of quenched disorder as parametrized by the critical current density ratio jc/jo drastically changes the dynamic behavior of the vortex system (jc and jo denote the depinning and depairing current densities). We discuss the equilibrium statistical mechanics (vortex lattice melting) and the dynamic behavior (creep) of the vortex system with a particular emphasis on the role of quantum fluctuations. © 1994.
Fluctuations and disorder in high temperature superconductors
Generically Dependent Continuant
RDF description of Fluctuations and disorder in high temperature superconductors - http://orbis.uaslp.mx/vivo/individual/scopus427
Article
Information Content Entity