Related papers: Vortex rectification effects in films with periodi…
A vortex-induced transverse voltage in a superconducting film, previously predicted theoretically, has been seen experimentally for the first time. The magnitude of this voltage and its nonmonotonic current dependence are explained on the…
We propose a description of the vortex dynamics in YBCO films from the critical to the normal states. This description supposes that the vortex motion is thermally activated along the twin boundaries of the films. The discontinuity observed…
We show that a remarkable variety of dynamical phenomena, including switching, polarization, symmetry locking, and dynamically induced pinning, can occur for vortices in type-II superconductors in the presence of a honeycomb pinning array…
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…
Understanding and controlling vortex motion in superconductors are important both for suppressing dissipation in superconducting devices and for device applications that exploit vortices. In this work, we quantitatively imaged the stray…
We derive the response of the magnetic superconductors in the vortex state to the ac Lorentz force, $F_L(t)=F_{{\rm ac}}\sin(\omega t)$, taking into account the interaction of vortices with the magnetic moments described by the relaxation…
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…
An advanced mask-less nanofabrication technique, focused electron beam-induced deposition (FEBID), has been employed on epitaxial Nb thin films for their ferromagnetic decoration by an array of Co stripes. These substantially modify the…
We have measured periodic oscillations of rectified dc voltage versus magnetic field V_{dc}(B) in a superconducting aluminum thin-film circular-asymmetric figure-of-eight microstructure threaded by a magnetic flux and biased with a…
We investigate the effects related to vortex core deformations when vortices approach each other. As a result of these vortex core deformations, the vortex-vortex interaction effectively acquires an attractive component leading to a variety…
We study the transport properties of a superconducting Nb film with a square lattice of artificial pinning centers (APCs) as a function of dc current, at a temperature close to the superconducting transition temperature of the film. We find…
Ratchet effect, observed in many systems starting from living organism to artificially designed device, is a manifestation of motion in asymmetric potential. Here we report results of a conductivity study of Polypyrrole nanowires, which…
Vortices in superconductors driven at microwave frequencies exhibit a response related to the interplay between the vortex viscosity, pinning strength, and flux creep effects. At the same time, the trapping of vortices in superconducting…
We investigate the dynamics of quantum particles in a ratchet potential subject to an ac force field. We develop a perturbative approach for weak ratchet potentials and force fields. Within this approach, we obtain an analytic description…
We measure the interaction of a single superfluid vortex with surface irregularities. While vortex pinning in superconductors usually becomes weaker at higher temperatures, we find the opposite behavior. The pinning steadily increases…
The effect of the Hall force on the pinning of vortices in type II superconductors is considered. A field theoretic formulation of the pinning problem allows a non-perturbative treatment of the influence of quenched disorder. A…
Driven vortex lattices have been studied in a material with strong pinning, such as Nb films. Samples in which natural random pinning coexists with artificial ordered arrays of defects (submicrometric Ni dots) have been fabricated with…
We investigate nonlocal vortex motion in weakly pinning a-NbGe nanostructures, which is driven by a transport current I and remotely detected as a nonlocal voltage Vnl. At high I, the measured Vnl exhibits dramatic sign reversals that at…
The use of artificial defects is known to enhance the superconducting critical parameters of thin films. In the case of conventional superconductors, regular arrays of submicron holes (antidots) substantially increase the critical…
The vortex patterns stabilized by the square array of artificial pinning sites with a tunable pinning strength are studied by using a phenomenological approach in the London limit. The transitions between pinned and deformed triangular…