相关论文: Creation and pinning of vortex-antivortex pairs
We investigate theoretically vortex-antivortex (v-av) matter moving in thin superconducting films with a regular array of in-plane magnetic dipoles. Our model considers v-av pair creation induced by the local current density generated by…
Antagonistic symmetries of superconducting polygons and their induced multi-vortex states in a homogeneous magnetic field may lead to appearance of antivortices in the vicinity of the superconducting/normal state boundary (where mesoscopic…
We investigate vortex pinning in thin superconducting films with a square array of rectangular submicron holes ("antidots"). Two types of antidots are considered: antidots fully perforating the superconducting film, and "blind antidots",…
We report the formation of a pinned vortex liquid spanning a very large region of the magnetic field-temperature parameter space in a 5 nm thick amorphous superconducting Re_xZr (x~6) (a-ReZr) thin film, using a combination of…
We study the pinning of vortices in thin film superconductors by magnetic dots in the London approximation. A single dot is in general able to pin multiple field-induced vortices, up to a saturation number n_s, which can be much larger than…
The vortex dynamics in superconducting films deposited on top of a five-fold Penrose array of magnetic dots is studied by means of transport measurements. We show that in the low pinning regime (demagnetized dots) a few periodic and…
We consider a thin superconducting film with a magnetic dot with permanent magnetization (normal to the film) placed on it by a method based on London-Maxwell equations. For sufficiently high dot magnetization a single vortex appears in the…
The interaction between a superconducting vortex or antivortex in a superconducting film and a magnetic dipole with in- or out-of-plane magnetization is investigated within the London approximation. The dependence of the interaction energy…
Using Ginzburg-Landau theory, we find novel configurations of vortices in superconducting thin films subject to the magnetic field of a magnetic dot array, with dipole moments oriented perpendicular to the film. Sufficiently strong magnets…
The interactions between vortices in a thin superconducting film and one magnetic dipole in the presence of a magnetic field applied parallel to the film surfaces are studied theoretically in the London limit. The dipole magnetic moment is…
\\A simple model for a superconductor with tunable critical current is studied theoretically. The model consists of a thin superconducting film with one vortex interacting with one magnetic dipole, whose magnetic moment is free to rotate,…
Novel vortex structures are found when a thin superconducting film (SC) is covered with a lattice of out-of-plane magnetized magnetic dots (MDs). The stray magnetic field of the dots confines the vortices to the MD regions, surrounded by…
The interaction between a straight vortex line in a superconducting film and a soft magnetic nanodisk in the magnetic vortex state in the presence of a magnetic field applied parallel to the film surfaces is studied theoretically. The…
In order to compare magnetic and non-magnetic pinning we have nanostructured two superconducting films with regular arrays of pinning centers: Cu (non-magnetic) dots in one case, and Py (magnetic) dots in the other. For low applied magnetic…
We investigate the transport properties of superconducting films with periodic arrays of in-plane magnetized micromagnets. Two different magnetic textures are studied: a square array of magnetic bars and a close-packed array of triangular…
Nb films containing extended arrays of holes with 45-nm diameter and 100-nm spacing have been fabricated using anodized aluminum oxide (AAO) as substrate. Pronounced matching effects in the magnetization and Little-Parks oscillations of the…
We report on the superior vortex pinning of single and multilayer Ba(Fe1-xCox)2As2 thin films with self-assembled c-axis and artificially introduced ab-plane pins. Ba(Fe1-xCox)2As2 can accept a very high density of pins (15-20 vol%) without…
We characterize the mechanisms of vortex pinning in a superfluid thin film described by the two-dimensional Gross-Pitaevskii equation. We consider a vortex "scattering experiment" whereby a single vortex in a superfluid flow interacts with…
Current-voltage (I-V) characteristics of quench condensed, superconducting, ultrathin Bi films in a magnetic field are reported. These show hysteresis for all films, grown both with and without thin Ge underlayers. Films on Ge underlayers,…
The hot-electron vortex flow instability in superconducting films in magnetic field $B$ at substrate temperature $T_0 \ll T_c$ is theoretically considered in the presence of pinning. The magnetic field dependence of the instability critical…