ESPCI web site
February 20 at 2:00 pm (Paris time)
Room Boreau, building C, 2nd floor
Quantum vortices in superconductors : Microscopic insights
The quantum nature of matter often results in phenomena that appear counter-intuitive with respect to our every-day life experience. Macroscopic quantum condensates (superconductors, superfluids, Bose-Einstein condensates of atoms, ions, polaritons, etc.) show, when rotated, a very peculiar collective response. Instead of spinning like tea in the cup, they make spontaneously appearing vortices – nanoscale quantum tornados which, in the case of superconductors, are often associated with the magnetic flux quanta.
In the lecture, a few well-known experimental evidences of vortices in quantum condensates will be presented, followed by a minimalistic theoretical description of a single quantum vortex in a superconductor. Then, we will illustrate the wide field of vortex-related phenomena by two examples of experimental studies of vortices on the local scale by Scanning Tunneling and Magnetic Force Microscopies, i - Spontaneous vortex-antivortex formation in ferromagnetic superconductor EuFe_2(As_0.79 P_0.21)_2 and , ii – discovery and applications of quantum vortices outside condensates in the so-called Josephson proximity junctions - two superconductors linked by a non-superconducting metal.
