相关论文: Effects of Columnar Pins on Flux Line Dynamics
A flux line in a Type-II superconductor with a single nonuniform columnar defect is studied by a perturbative diagrammatic expansion around an annealed approximation. The system undergoes a finite temperature depinning transition for the…
The effect of columnar pins on the flux-lines melting transition in high-temperature superconductors is studied using Path Integral Monte Carlo simulations. We highlight the similarities and differences in the effects of columnar disorder…
We study the effect of a single columnar pin on a $(1+1)$ dimensional array of vortex lines in planar type II superconductors in the presence of point disorder. In large samples, the pinning is most effective right at the temperature of the…
We use the Feynman--Kleinert variational method [R.P. Feynman and H. Kleinert, Phys. Rev. A {\bf 34}, 5080, (1986)] to calculate the partition function and effective pinning energy of a single flux line near a columnar pin in type II…
Theoretical work predicts that the strong dependence of Tc on pure shear strain within the a-b plane of optimally doped YBa2Cu3O{7-delta} results in heterogenous columnar pins of vortex lines about dislocation lines and about nano-columns…
The role of commensurability and the interplay of correlated disorder and interactions on vortex dynamics in the presence of columnar pins is studied via molecular dynamics simulations. Simulations of dynamics reveal substantial caging…
Vortex lines in type-II superconductors display complicated relaxation processes due to the intricate competition between their mutual repulsive interactions and pinning to attractive point or extended defects. We perform extensive Monte…
We investigate the dynamics of interacting magnetic flux lines driven by an external current in the presence of linear pinning centers, arranged either in a periodic square lattice or placed randomly in space, by means of three-dimensional…
We study the effects of splayed columnar pins on the vortex motion using realistic London Langevin simulations. At low currents vortex creep is strongly suppressed, whereas the critical current j_c is enhanced only moderately. Splaying the…
We calculate the degree of flux pinning by defects in model high-temperature superconductors (HTSC's). The HTSC is modeled as a three-dimensional network of resistively-shunted Josephson junctions in an external magnetic field,…
We discuss the low-temperature dynamics of magnetic flux lines in high-temperature superconductors in the presence of a family of parallel twin planes that contain the $c$ axis. A current applied along the twin planes drives flux motion in…
Low-temperature dynamics of flux lines in high temperature, type II, superconductors in the presence of correlated disorder in the form of columnar defects is discussed. The effect of tilting the applied magnetic field with respect to the…
Columnar defects provide effective pinning centers for magnetic flux lines in high--$T_{\rm c}$ superconductors. Utilizing a mapping of the statistical mechanics of directed lines to the quantum mechanics of two--dimensional bosons, one…
We use numerical minimization of a model free energy functional to study the effects of columnar pinning centers on the structure and thermodynamics of a system of pancake vortices in the mixed phase of highly anisotropic layered…
We report on flux confinement effects in superconducting submicron line, loop and dot structures. The main idea of our study was to vary the boundary conditions for confinement of the superconducting condensate by taking samples of…
The equilibrium properties of flux lines pinned by columnar disorder are studied, using the analogy with the time evolution of a diffusing scalar density in a randomly amplifying medium. Near H_{c1}, the physical features of the vortices in…
To better understand vortex pinning in thin superconducting slabs, we study the interaction of a single fluctuating vortex filament with a curved line defect in (1+1) dimensions. This problem is also relevant to the interaction of scratches…
The pinning of flux lines by two different types of regular arrays of submicron magnetic dots is studied in superconducting Pb films; rectangular Co dots with in-plane magnetization are used as pinning centers to investigate the influence…
We study the effects of weak columnar and point disorder on the vortex-lattice phase transitions in high temperature superconductors. The combined effect of thermal fluctuations and of quenched disorder is investigated using a simplified…
We explore the effects of sample dimensionality on vortex pinning in a type-II, low-$T_C$, s-wave superconductor, NbN, in the presence of a perpendicular magnetic field, $H$. We find significant differences in the phase diagrams in the…