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TT: Tiefe Temperaturen
TT 33: Superconductivity: Vortex Dynamics, Vortex Phases, Pinning
TT 33.7: Talk
Friday, March 31, 2006, 11:45–12:00, HSZ 304
Defect Melting of Vortices in High-Tc Superconductors — •Jürgen Dietel and Hagen Kleinert — Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
We set up a melting model for vortex lattices in high-temperature superconductors based on the continuum elasticity theory. The model is Gaussian and includes defect fluctuations by means of a discrete-valued vortex gauge field. We derive the melting temperature of the lattice and predict the size of the Lindemann number. Our result agrees well with experiments for YBa2 Cu3 O7−δ , and with modifications also for Bi2 Sr2 Ca Cu2 O8 . We calculate the jumps in the entropy and the magnetic induction at the melting transition.