Physics of vortices in superconducting nanostructures
by Dimitri Roditchev (in coll. with T. Cren, Y. Noat, F. Debontridder and L. Serrier-Garcia)
Institut des Nanosciences de Paris, UMR75-88 CNRS, University Pierre et Marie Curie Paris 6 UPMC, 4 place Jussieu 75005 Paris FRANCE
The vortices are general features of rotating quantum condensates such as suprefluids, cold atoms, or superconductors in magnetic field. They are subject of important experimental and theoretical effort since the discovery of superconductivity and superfluidity. The vortex characteristics, their individual and collective behaviour in superconductors are discussed. At the end of the first lecture, the ways to observe individual vortices in the real space, to follow their evolution by Scanning Tunneling Microscopy (STM) and Spectroscopy (STS) experiments are considered.
In the second part, the results of vortex observation in superconductors by STM/STS are presented. First, the microscopic characteristics of individual vortices are discussed, followed by the data describing their collective behaviour. Finally, the most recent results on confinement effects on the vortex phase diagram in nano-sized superconductors are presented.
The outline of the talk:
1.1. Quantum condensates. Conventional Superconductivity. Ground state and rotating condensates.
1.2.Vortices. Ginzburg-Landau phenomenological theory. Vortex structure and interaction. Abrikosov vortex lattice: conventional case, high-Tc superconductors.
1.3.Tunneling spectroscopy. Giaver’ tunneling experiment. Scanning Tunneling Micrscopy and Spectroscopy: What does it measure?