Preferentially directed flux motion in a very thin superconducting strip with nanostructured profile

Sabatino, P.; Carapella, G.; Gombos, M.

doi:10.1063/1.4759206

Cited by 13 publications

(8 citation statements)

References 61 publications

(66 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These contour plots clearly demonstrate that the presence of indents induces the rectification of vortex motion over a wide range of magnetic fields. In contrast to that, the reference sample exhibits a very weak rectification signal probably originating from unavoidable imperfections of the nominally flat sample borders, in agreement with previous reports [13,14,26] or from the fact that placing both voltage contacts at one side of the bridge leads also to breaking the inversion symmetry [27,28].…”

Section: Resultssupporting

confidence: 90%

Vortex ratchet induced by controlled edge roughness

et al. 2013

View full text Add to dashboard Cite

We demonstrate theoretically and experimentally the generation of rectified mean vortex displacement resulting from a controlled difference between the surface barriers at the opposite borders of a superconducting strip. Our investigation focuses on Al superconducting strips where, in one of the two sample borders, a saw tooth-like array of micro-indentations has been imprinted. The origin of the vortex ratchet effect is based on the fact that (i) the onset of vortex motion is mainly governed by the entrance/nucleation of vortices and (ii) the current lines bunching produced by the indentations facilitates the entrance/nucleation of vortices. Only for one current direction the indentations are positioned at the side of vortex entry and the onset of the resistive regime is lowered compared to the opposite current direction. This investigation points to the relevance of ubiquitous border effects typically neglected when interpreting vortex ratchet measurements on samples with arrays of local asymmetric pinning sites. 5

show abstract

Section: Resultssupporting

confidence: 90%

Vortex ratchet induced by controlled edge roughness

et al. 2013

View full text Add to dashboard Cite

show abstract

“…By contrast, a rare ratchet effect produced by relatively large triangle antidots in YBCO thin films has the maximum operating field for their ratchet effect between ∼0.07 T at 0.86 T c and ∼0.15 T at 0.56 T c , assuming a T c of 90 K for their samples. Similar ineffective results for ratcheting were obtained in sawtooth-like thin Nb structures fabricated by sputtering employing a bilayer resist shadow mask . Thus, the superconducting ratchet created by our sawtooth structures is far functionally superior and promising in operating magnetic field compared to antidot ratchets ,, and to the only other known sawtooth-like ratchet fabricated from Nb …”

Section: Discussionsupporting

confidence: 75%

“…Similar ineffective results for ratcheting were obtained in sawtooth-like thin Nb structures fabricated by sputtering employing a bilayer resist shadow mask. 40 Thus, the superconducting ratchet created by our sawtooth structures is far functionally superior and promising in operating magnetic field…”

Section: ■ Conclusionmentioning

confidence: 96%

Guided Vortex Motion Control in Superconducting Thin Films by Sawtooth Ion Surface Modification

Jones

Lam

et al. 2020

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Design of flux profile and guided motion of magnetic flux quanta (also known as vortices) are central issues for functionality of superconducting devices. Anchoring vortex movement by trapping flux lines through the use of defects and preventing vortex entry by shielding magnetic field have been broadly explored, which can also enable reduction of noise for optimal device operation. Removing vortices entirely via the so-called ratchet effect (employing an asymmetric energy potential) is another alternative. This ratcheting potential is also used in DNA splitting, particle separation, surface atom electromigration, and electrophoresis. Utilizing a superconductor with the ratchet vortex pinning potential induces a dominant motion direction, which can be used to pump flux out from device functional zones. In this work, a varying thickness superconductor with its tailored intrinsic pinning mechanism has been simulated and proven to provide this preferential vortex motion. We demonstrate both theoretically and experimentally that a varying thickness superconducting ratchet is indeed possible. Furthermore, the sawtooth shape of the bridge provides a tunability to the preferred vortex motion direction, dependent on the ramp gradient and intrinsic pinning strength.

show abstract

“…2(b) we show the V ( I ) curves in the low voltage region for values of applied magnetic field ranging from B = 0 to B = 9.76 mT. We checked that no asymmetry or magnetic field-induced hysteresis 44 45 46 47 48 was present in the V ( I ) curves when magnetic field direction was reversed or a full magnetic loop was performed. This reassures us that the field sensed by the weak link is really homogeneous, the Py rests in a single domain state, and the thickness profile of thin Nb film is flat.…”

Section: Resultsmentioning

confidence: 99%

Current driven transition from Abrikosov-Josephson to Josephson-like vortex in mesoscopic lateral S/S’/S superconducting weak links

Carapella

Sabatino

Barone

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

Vortices are topological defects accounting for many important effects in superconductivity, superfluidity, and magnetism. Here we address the stability of a small number of such excitations driven by strong external forces. We focus on Abrikosov-Josephson vortex that appears in lateral superconducting S/S’/S weak links with suppressed superconductivity in S’. In such a system the vortex is nucleated and confined in the narrow S’ region by means of a small magnetic field and moves under the effect of a force proportional to an applied electrical current with a velocity proportional to the measured voltage. Our numerical simulations show that when a slow moving Abrikosov-Josephson vortex is driven by a strong constant current it becomes unstable with respect to a faster moving excitation: the Josephon-like vortex. Such a current-driven transition explains the structured dissipative branches that we observe in the voltage-current curve of the weak link. When vortex matter is strongly confined phenomena as magnetoresistance oscillations and reentrance of superconductivity can possibly occur. We experimentally observe these phenomena in our weak links.

show abstract

Preferentially directed flux motion in a very thin superconducting strip with nanostructured profile

Cited by 13 publications

References 61 publications

Vortex ratchet induced by controlled edge roughness

Vortex ratchet induced by controlled edge roughness

Guided Vortex Motion Control in Superconducting Thin Films by Sawtooth Ion Surface Modification

Current driven transition from Abrikosov-Josephson to Josephson-like vortex in mesoscopic lateral S/S’/S superconducting weak links

Contact Info

Product

Resources

About