Vortex Matter
Vortex matter refers to the state of matter where the magnetic field penetrates a superconducting condensate creating vortices. When the dimensions of the superconducting condensate are comparable to the coherence length only few vortices can coexist in the system. As shown in the figure and in contrast to the usual triangular arrangement in bulk, complex and unique vortex structures are expected to occur due to the competition between geometric confinement and vortex-vortex interaction. Many interesting analogies can be drawn between artificial atoms, type-II superconducting mesoscopic disks in perpendicular magnetic fields, or rotating Bose-Einstein condensates where the role of the electron is played in the latter cases, not by the Cooper pairs or the bosons, but by the vortices.
Some representative publications:
Magnetic field-induced dissipation-free state in superconducting nanostructures, R Córdoba, TI Baturina, J Sesé, A Yu Mironov, JM De Teresa, MR Ibarra, ... Nature communications 4 (1), 1437 (2013).
Critical fields for vortex expulsion from narrow superconducting strips, Sanchez-Lotero, P.; Palacios, J. J., Physical Review B, 75 (2007)
Fine structure in magnetization of individual fluxoid states, Geim, A. K.; Dubonos, S. V.; Palacios, J. J.; et al., Physical Review Letters 85, 1528-1531 (2000).
Metastability and paramagnetism in superconducting mesoscopic disks, Palacios, J. J., Physical Review Letters 84,1796-1799 (2000).
Vortex matter in superconducting mesoscopic disks: Structure, magnetization, and phase transitions, JJ Palacios, Physical Review B 58, R5948 (1998).