2010/03/02 by Mark Sweeney, Mark C. Sweeney, Martin P. Gelfand · 5 citations
Physics and Astronomy · #Condensed matter physics #Diffraction #Hexagonal lattice #Lattice (music) #Magnetic properties of thin films #Mechanics #Phase (matter) #Phase diagram #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Reciprocal lattice #Square lattice #Superconductivity #Theoretical and Computational Physics #Type-II superconductor #Vortex #cond-mat.supr-con
paper · pdf · open access · doi:10.1103/physrevb.82.214508
published in Physical Review B 82(21) (American Physical Society) · 4 figures
arxiv created 2010/03/25 · openalex publication_date 2010/12/08 · arxiv updated 2015/03/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Sufficiently thin films of type-I superconductor in a perpendicular magnetic field exhibit a triangular vortex lattice while thick films develop an intermediate state. To elucidate what happens between these two regimes, precise numerical calculations have been made within Ginzburg-Landau theory at \ensuremathκ=0.5 and 0.25 for a variety of vortex lattice structures with one flux quantum per unit cell. The phase diagram in the space of mean induction and film thickness includes a narrow wedge in which a square lattice is stable, surrounded by the domain of stability of the triangular lattice at thinner films/lower fields and, on the other side, rectangular lattices with continuously varying aspect ratio. The vortex lattice has an anomalously small shear modulus within and close to the square lattice phase. Solutions of the Ginzburg-Landau equations have been obtained by similar calculations for bulk systems and thin films with one vortex but two flux quanta per square or triangular unit cell. Primitive lattices of double-fluxoid vortices are thermodynamically unstable in bulk in both type-I and type-II superconductors, as expected. In type-I films these double-fluxoid lattices do not pre-empt the single-fluxoid lattice structures.