M. V. Milošević

Vortex configurations and critical parameters in superconducting thin films containing antidot arrays: Nonlinear Ginzburg-Landau theory

Using the non-linear Ginzburg-Landau (GL) theory, we obtain the possible vortex configurations in superconducting thin films containing a square lattice of antidots. The equilibrium structural phase diagram is constructed which gives the different ground-state vortex configurations as function of the size and periodicity of the antidots for a given effective GL parameter

Two-Band Superconductors: Hidden Criticality Deep in the Superconducting State

\kappa^{*}

Magnetic pinning of vortices in a superconducting film: The (anti)vortex-magnetic dipole interaction energy in the London approximation

. Giant-vortex states, combination of giant- and multi-vortex states, as well as symmetry imposed vortex-antivortex states are found to be the ground state for particular geometrical parameters of the sample. The antidot occupation number

Vortex matter in mesoscopic two-gap superconducting disks: influence of Josephson and magnetic coupling

n_o

The Ginzburg–Landau theory in application

is calculated as a function of related parameters and comparison with existing expressions for the saturation number

Field-enhanced critical parameters in magnetically nanostructured superconductors

n_s

Large Magnetoresistance Oscillations in Mesoscopic Superconductors due to Current-Excited Moving Vortices

and with experimental results is given. For a small radius of antidots a triangular vortex lattice is obtained, where some of the vortices are pinned by the antidots and some of them are located between them. Transition between the square pinned and triangular vortex lattices is given for different values of the applied field. The enhanced critical current at integer and rational matching fields is found, where the level of enhancement at given magnetic field directly depends on the vortex-occupation number of the antidots. For certain parameters of the antidot lattice and/or temperature the critical current is found to be larger for higher magnetic fields. Superconducting/normal

Local current injection into mesoscopic superconductors for the manipulation of quantum states.

H-T

Symmetric and asymmetric vortex-antivortex molecules in a fourfold superconducting geometry

phase boundary exhibits different regimes as antidots are made larger, and we transit from a plain superconducting film to a thin-wire superconducting network. Presented results are in good agreement with available experiments and suggest possible new experiments.

Interaction between a superconducting vortex and an out-of-plane magnetized ferromagnetic disk: Influence of the magnet geometry

We show that two-band superconductors harbor hidden criticality deep in the superconducting state, stemming from the critical temperature of the weaker band taken as an independent system. For sufficiently small interband coupling γ the coherence length of the weaker band exhibits a remarkable deviation from the conventional monotonic increase with temperature, namely, a pronounced peak close to the hidden critical point. The magnitude of the peak scales as ∝γ-μ, with the Landau critical exponent μ=1/3, the same as found for the mean-field critical behavior with respect to the source field in ferromagnets and ferroelectrics. Here reported hidden criticality of multiband superconductors can be experimentally observed by, e.g., imaging of the variations of the vortex core in a broader temperature range. Similar effects are expected for the superconducting multilayers.