Classical analogy for the deflection of flux avalanches by a metallic layer

Brisbois, Jérémy; Vanderheyden, Benoît; Colauto, F.; Motta, M.; Ortiz, W.A.; Fritzsche, Joachim; Nguyen, Ngoc Duy; Hackens, Benoît; Adami, O.-A.; Silhanek, Alejandro

doi:10.1088/1367-2630/16/10/103003

Cited by 14 publications

(26 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 of Ref. [2]), giving rise to a drag force ηv, where η is the damping coefficient, constant in this velocity regime. At high monopole velocities, v/w 1, only the positive image * jbrisbois@ulg.ac.be located just below the monopole remains, and the drag force tends to zero, i.e., η → 0.…”

Section: Introductionmentioning

confidence: 85%

“…To that end, we first extend our previous investigation [2] by exploring the variations of the conductivity and thickness of a metallic layer deposited on top of the superconductor. Interestingly, these measurements suggest that certain precautions need to be taken to ensure that the invasiveness of the magneto-optical imaging (MOI) technique remains at a minimum level [19].…”

Section: Introductionmentioning

confidence: 97%

“…It has been shown recently that magnetic flux avalanches triggered in a superconducting film are diverted from their initial trajectory when they encounter a conductive layer deposited on top of the superconductor, but electrically insulated from it [1][2][3][4]. This phenomenon arises from the electromagnetic braking of the flux propagation, caused by the eddy currents induced in the conductive layer [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…This phenomenon arises from the electromagnetic braking of the flux propagation, caused by the eddy currents induced in the conductive layer [5][6][7][8]. The question as to whether a single element of the flux front, i.e., a superconducting vortex, could also undergo any deflection of its trajectory when entering in the region covered by a conducting layer has recently been tackled by appealing to a classical analogy, consisting of a magnetic monopole (the vortex) moving in the vicinity of a metallic film [2].…”

Section: Introductionmentioning

confidence: 99%

“…However, in the high-speed regime, the nature of the vortex changes, the temperature rises locally, and the classical analogy brought up in Ref. [2] is no longer strictly valid. An alternative way to explore the high-velocity regime while keeping the Abrikosov vortex structure is to substantially decrease w, either by increasing σ or t. Notice, however, that when t becomes comparable to the skin depth, further increase of the metal thickness will not impact w. In this context, it is interesting to consider the limiting case of a conductive layer with infinite conductivity, where the damping contribution of the eddy currents becomes negligible, in opposition to the velocity-dependent case when using a normal metal.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Flux penetration in a superconducting film partially capped with a conducting layer

et al. 2017

View full text Add to dashboard Cite

The influence of a conducting layer on the magnetic flux penetration in a superconducting Nb film is studied by magneto-optical imaging. The metallic layer partially covering the superconductor provides an additional velocity-dependent damping mechanism for the flux motion that helps to protect the superconducting state when thermomagnetic instabilities develop. If the flux advances with a velocity slower than w = 2/μ 0 σ t, where σ is the cap layer conductivity and t is its thickness, the flux penetration remains unaffected, whereas for incoming flux moving faster than w, the metallic layer becomes an active screening shield. When the metallic layer is replaced by a perfect conductor, it is expected that the flux braking effect will occur for all flux velocities. We investigate this effect by studying Nb samples with a thickness step. Some of the observed features, namely the deflection of the flux trajectories at the border of the thick center, as well as the favored flux penetration at the indentation, are reproduced by time-dependent Ginzburg-Landau simulations.

show abstract

Section: Introductionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Flux penetration in a superconducting film partially capped with a conducting layer

et al. 2017

View full text Add to dashboard Cite

show abstract

Suppression of flux avalanches in YBCO superconducting thin films by coating metal investigated using magneto-optical imaging

Ran,

Jing,

Shen

et al. 2024

Superconductivity

View full text Add to dashboard Cite

Imprinting superconducting vortex footsteps in a magnetic layer

Brisbois

Motta

Avila

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit cards and computer hard drives. Here we experimentally show that a similar principle can be applied for imprinting the trajectory of quantum units of flux (vortices), travelling in a superconducting film (Nb), into a soft magnetic layer of permalloy (Py). In full analogy with the magnetic drawing board, vortices act as tiny magnetic scribers leaving a wake of polarized magnetic media in the Py board. The mutual interaction between superconducting vortices and ferromagnetic domains has been investigated by the magneto-optical imaging technique. For thick Py layers, the stripe magnetic domain pattern guides both the smooth magnetic flux penetration as well as the abrupt vortex avalanches in the Nb film. It is however in thin Py layers without stripe domains where superconducting vortices leave the clearest imprints of locally polarized magnetic moment along their paths. In all cases, we observe that the flux is delayed at the border of the magnetic layer. Our findings open the quest for optimizing magnetic recording of superconducting vortex trajectories.Quantum magnetic flux units in type-II superconductors can be regarded as small solenoids, producing localized magnetic field variations extending over distances of 2λ perpendicularly to the applied field, where λ is the magnetic penetration depth. These flux lines interact with inhomogeneities inside the superconducting material, leading to a plethora of well-known pinning mechanisms. Furthermore, the static and dynamic response of individual vortices can also be modified if their stray field outside the superconducting volume is altered. This is precisely the reason why multilayered hybrid systems combining superconducting and non-superconducting materials have been an active field of research in the last decade.It has been shown, for instance, that the stray field of an isolated moving vortex can induce eddy currents in a nearby metallic layer, leading to a velocity dependent damping force 1,2 . This effect can be exploited to provide better stability and quench protection in superconducting cables by reducing the speed of flux jumps 3,4 . More spectacular is the possible use of the monopolar magnetic field emanating from a vortex as a submicron-sized magnetic tweezers to locally polarize spin carriers in a diluted magnetic semiconductor 5 . Among these hybrid devices, the heterostructures combining superconductivity and magnetism, two antagonistic quantum macroscopic states, arguably represent the most investigated systems so far [6][7][8][9] . A simple attempt to classify the superconductor (S-layer) -ferromagnet (F-layer) hybrids, where the F-layer and the S-layer are in close proximity and interact only through their stray fields, consists of comparing the relative field strength scales of each subsystem. Indeed, if the coercive field, H coe , of the ferromag...

show abstract

Classical analogy for the deflection of flux avalanches by a metallic layer

Cited by 14 publications

References 37 publications

Flux penetration in a superconducting film partially capped with a conducting layer

Flux penetration in a superconducting film partially capped with a conducting layer

Suppression of flux avalanches in YBCO superconducting thin films by coating metal investigated using magneto-optical imaging

Imprinting superconducting vortex footsteps in a magnetic layer

Contact Info

Product

Resources

About