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We analyze the vortex dynamics in superconducting thin films with a periodic array of pinning centers. In particular, we study the effect of anisotropy for a Kagom\'e pinning network when longitudinal and transverse transport currents are…

Superconductivity · Physics 2011-12-22 R. P. Simões , P. A. Venegas , D. F. Mello

Rectangular pinning arrays of Ni dots define a potential landscape for vortex motion in Nb films. Magnetotransport experiments in which two in-plane orthogonal electrical currents are injected simultaneously allow selecting the direction…

Superconductivity · Physics 2009-11-10 J. E. Villegas , E. M. Gonzalez , M. I. Montero , Ivan K. Schuller , J. L. Vicent

A serious obstacle that impedes the application of low and high temperature superconductor (SC) devices is the presence of trapped flux. Flux lines or vortices are induced by fields as small as the Earth's magnetic field. Once present,…

Superconductivity · Physics 2009-10-31 Choongseop Lee , Boldizsar Janko , Imre Derenyi , Albert-Laszlo Barabasi

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…

Two-dimensional vortex dynamics in a ratchet washboard planar pinning potential (PPP) in the presence of thermal fluctuations is considered on the basis of a Fokker-Planck equation. Explicit expressions for two new nonlinear anisotropic…

Superconductivity · Physics 2010-06-16 Valerij A. Shklovskij , Vladimir V. Sosedkin

Pinning interactions between superconducting vortices in Nb and magnetic Ni dots were studied as a function of current and temperature to clarify the nature of pinning mechanisms. A strong current dependence is found for a square array of…

Superconductivity · Physics 2009-10-31 J. I. Martin , M. Velez , A. Hoffmann , I. K. Schuller , J. L. Vicent

A conformal pinning array can be created by conformally transforming a uniform triangular pinning lattice to produces a new structure in which the six-fold ordering of the original lattice is conserved but where there is a spatial gradient…

Superconductivity · Physics 2017-12-06 C. J. Olson Reichhardt , Y. L. Wang , Z. L. Xiao , W. K. Kwok , D. Ray , C. Reichhardt , B. Janko

We study the vortex pinning effect in a Bose-Einstein Condensate in the presence of a rotating lattice potential by numerically solving the time-dependent Gross-Pitaevskii equation. We consider a triangular lattice potential created by…

Other Condensed Matter · Physics 2009-11-13 T. Sato , T. Ishiyama , T. Nikuni

Abnormal magnetoresistance behavior is found in superconducting Nb films perforated with rectangular arrays of antidots (holes). Generally magnetoresistance were always found to increase with increasing magnetic field. Here we observed a…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 W. J. Zhang , S. K. He , B. H. Li , F. Cheng , B. Xu , Z. C. Wen , W. H. Cao , X. F. Han , S. P. Zhao , X. G. Qiu

In a nanopillar with dipolarly coupled vortices, we present an experimental and simulation study to understand how the interplay between the bias field and spin transfer torque impacts reversal of the vortex cores. We find that, depending…

Mesoscale and Nanoscale Physics · Physics 2015-06-12 N. Locatelli , A. E. Ekomasov , A. V. Khvalkovskiy , Sh. A. Azamatov , K. A. Zvezdin , J. Grollier , E. G. Ekomasov , V. Cros

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…

Superconductivity · Physics 2009-11-07 W. V. Pogosov , A. L. Rakhmanov , V. V. Moshchalkov

It has been predicted that superconducting vortices should be electrically charged and that this effect is particularly enhanced for, high temperature superconductors.\cite{kho95,bla96} Hall effect\cite{hag91} and nuclear magnetic resonance…

Superconductivity · Physics 2015-05-20 A. M. Mounce , S. Oh , S. Mukhopadhyay , W. P. Halperin , A. P. Reyes , P. L. Kuhns , K. Fujita , M. Ishikado , S. Uchida

A controlled local enhancement of superconductivity yields unexpected modifications in the vortex dynamics. This local enhancement has been achieved by designing an array of superconducting Nb nanostructures embedded in a V superconducting…

In 1976 Larkin and Ovchinnikov [Sov. Phys. JETP 41, 960 (1976)] predicted that vortex matter in superconductors driven by an electrical current can undergo an abrupt dynamic transition from a flux-flow regime to a more dissipative state at…

We have studied the deterministic dynamics of underdamped single and multiparticle ratchets associated with current reversal, as a function of the amplitude of the external driving force. Two experimentally inspired methods are used. In the…

Condensed Matter · Physics 2009-11-07 H. A. Larrondo , Fereydoon Family , C. M. Arizmendi

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…

Superconductivity · Physics 2009-11-11 Gilson Carneiro

The controlled motion of objects through narrow channels is important in many fields. We have fabricated asymmetric weak-pinning channels in a superconducting thin-film strip for controlling the dynamics of vortices. The lack of pinning…

Superconductivity · Physics 2009-06-18 K. Yu , T. W. Heitmann , C. Song , M. P. DeFeo , B. L. T. Plourde , M. B. S. Hesselberth , P. H. Kes

A dc voltage drop develops along amorphous indium oxide nanowires that are exposed to an ac bias source. This voltage is anti-symmetric with magnetic field and is characterized by sample specific quasi-periodic magneto-voltage oscillations.…

Superconductivity · Physics 2015-05-20 Shachaf Poran , Efrat Shimshoni , Aviad Frydman

Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. Additionally, the exchange coupling of magnetic vortices to…

Hybrid magnetic arrays embedded in superconducting films are ideal systems to study the competition between different physical (such as the coherence length) and structural length scales such as available in artificially produced…