Controlling complex phases of correlated systems on ultra-short
timescales is an intriguing application of nonequilibrium ideas in
condensed matter physics. In this talk will focus on the control of
magnetic states. Magnetic order is determined by the exchange
interaction J, which emerges from the Coulomb interaction and the Pauli
principle. Driving the electrons out of equilibrium thus modifies J and
allows for ultra-fast manipulation of magnetism without using strong
magnetic fields.
Nucleation of the superconducting phase in a thin surface sheath in a decreasing magnetic field parallel to the sample surface was predicted by Saint-James and de Gennes fifty years ago. This prediction was confirmed in a short time after the paper’s publication. Nevertheless, the model for the ac losses in bulk samples in magnetic fields above Hc2 are still absent. Experiments with thin-walled superconducting cylinders can provide an essential simplification of this problem. Thin-walled hollow cylinders with macroscopic diameter have some advantages in research.