Guided vortex motion in high-Tc superconducting thin films and devices with special arrangements of artificial defects

Wördenweber, R.; Dymashevski, P.

doi:10.1016/j.physc.2003.11.024

Cited by 9 publications

(10 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indications for guided flux motion along rows of antidots have been previously obtained from Hall-type measurements of the flux transport in such films. 8 Here we directly prove that vortices are steered along rows of antidots. We also observe traces of "lost" vortices for small misorientation angle between rows of antidots and the direction of the bias current, i.e., large misorientation angles between the rows of antidots and the direction of the current-induced Lorentz force on the vortices.…”

Section: Introductionmentioning

confidence: 83%

Laser scanning microscopy of guided vortex flow in microstructured high-Tc films

Lukashenko

Ustinov

Zhuravel

et al. 2006

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

We report the visualization of guidance of vortices by artificial microholes ͑antidots͒ in superconducting thin films using a low-temperature laser scanning microscope. Previously, guided motion of vortices via tilted rows of antidots in YBa 2 Cu 3 O 7 films was detected indirectly by using resistive Hall-type measurements. Here we prove that vortices are steered between antidots into a priori chosen direction by imaging of resistive photoresponse with a spatial resolution down to about 1 m. We observe predominant paths for vortex motion. Vortices are nucleated and annihilated at antidots, i.e., antidots define starting and ending points of predominant vortex paths. Depending on the misorientation angle between rows of antidots and the current-driven direction of vortex motion, different channels dominate in antidot-guided vortex motion. Our experimental results can be explained by the n-channel model. Finally, we present direct measurements of the local critical currents. This technique can be used as a quantitative method for the analysis of vortex motion in micropatterned thin films.

show abstract

Section: Introductionmentioning

confidence: 83%

Laser scanning microscopy of guided vortex flow in microstructured high-Tc films

Lukashenko

Ustinov

Zhuravel

et al. 2006

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…1 It has been shown both theoretically and experimentally that, in a superconductor with an asymmetric periodic potential achieved by having asymmetric channel walls, a graduated random pinning density, or periodic arrays of asymmetric pinning defects, an applied transverse ac electric current can lead to a net dc longitudinal transport of vortices. 2 It has recently been demonstrated that rectification of ac currents can take place in thin films containing asymmetric chains of large micronsized antidots, 3 which is the motivation for the study reported here. The experimental realization of efficient vortex ratchets would enable a number of novel applications, including the removal of unwanted trapped flux in superconducting quantum interference devices ͑SQUIDs͒, 4 vortex pumps, and vortex lenses that can either disperse or concentrate vortices in chosen regions of a sample, 1 as well as collective vortex step motors.…”

Section: Introductionmentioning

confidence: 87%

Anisotropic vortex channeling inYBa2Cu3O7–δthin films with

et al. 2005

Self Cite

View full text Add to dashboard Cite

Scanning Hall probe microscopy has been used to make a microscopic study of flux structures and dynamics in yttrium barium copper oxide thin-film disks containing a regular 10-m-period square array of 2.5-m-sized holes ͑antidots͒. Images obtained after field cooling the sample to 77 K in very low fields reveal that the holes can trap two flux quanta at this temperature. Scans obtained after zero-field cooling ͑ZFC͒ to 77 K and a subsequent applied field cycle clearly display preferential flux channeling along chains of antidots in the direction of maximum induction gradient. Remarkably, upon reversal of field sweep direction, we observe flux "streaming" out of the holes towards the sample edges with almost uniform density flux "stripes" bridging the holes in the exit direction. We estimate that the antidots can preferentially trap about 15 flux quanta in these ZFC experiments. Classical electrodynamics simulations of our samples appear to be in good qualitative agreement with our results, indicating that many of the observed phenomena may be geometrical effects that depend primarily on the shape and topology of the sample, and potential applications are discussed.

show abstract

“…, Soroka and Huth[239], Vélez et al[240], Silhanek et al[241], Wördenweber et al[242]). Interestingly, the direction of the Lorentz force f L = c −1 [j × B] and the drift velocity of the vortex lattice do not generally coincide.…”

mentioning

confidence: 99%

Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids

Aladyshkin

Silhanek

Gillijns

et al. 2009

Supercond. Sci. Technol.

217

143

View full text Add to dashboard Cite

Abstract. The theoretical and experimental results concerning the thermodynamical and low-frequency transport properties of hybrid structures, consisting of spatially-separated conventional low-temperature superconductor (S) and ferromagnet (F), is reviewed. Since the superconducting and ferromagnetic parts are assumed to be electrically insulated, no proximity effect is present and thus the interaction between both subsystems is through their respective magnetic stray fields. Depending on the temperature range and the value of the external field Hext, different behavior of such S/F hybrids is anticipated. Rather close to the superconducting phase transition line, when the superconducting state is only weakly developed, the magnetization of the ferromagnet is solely determined by the magnetic history of the system and it is not influenced by the field generated by the supercurrents. In contrast to that, the nonuniform magnetic field pattern, induced by the ferromagnet, strongly affect the nucleation of superconductivity leading to an exotic dependence of the critical temperature Tc on Hext. Deeper in the superconducting state the effect of the screening currents cannot be neglected anymore. In this region of the phase diagram various aspects of the interaction between vortices and magnetic inhomogeneities are discussed. In the last section we briefly summarize the physics of S/F hybrids when the magnetization of the ferromagnet is no longer fixed but can change under the influence of the superconducting currents. As a consequence, the superconductor and ferromagnet become truly coupled and the equilibrium configuration of this "soft" S/F hybrids requires rearrangements of both, superconducting and ferromagnetic characteristics, as compared with "hard" S/F structures. Some figures in this paper are in color only in the electronic version.

show abstract

Guided vortex motion in high-Tc superconducting thin films and devices with special arrangements of artificial defects

Cited by 9 publications

References 22 publications

Laser scanning microscopy of guided vortex flow in microstructured high-Tc films

Laser scanning microscopy of guided vortex flow in microstructured high-Tc films

Anisotropic vortex channeling inYBa2Cu3O7–δthin films with

Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids

Contact Info

Product

Resources

About