Vortices in superconductors with a columnar defect: Finite size effects

Sardella, Edson; Freire, Rodrigo de Alvarenga; Lisboa‐Filho, Paulo Noronha

doi:10.1016/j.physc.2005.02.007

Cited by 5 publications

(3 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The repulsive force between the vortices is

F_{v v} true(r_{i} true) = f_{normalv} {true \sum}_{k true(\neq i true)}^{N_{normalv}} K_{1} true(\frac{| r_{i} - r_{k} |}{λ} true) \frac{r_{i} - r_{k}}{| r_{i} - r_{k} |} .

Here, r i is the position of i th vortex, f v is the unit force given by

f_{normalv} = {normalΦ}_{0}^{2} / 8 π^{2} λ^{3}

with

{normalΦ}_{0}

being the magnetic flux quantum, N v is the number of vortices, K 1 ( r / λ ) is a modified Bessel function, and | r i − r k | is the distance between the vortices i and k . The vortex‐pinning interaction is deduced from the force acting on a single vortex at the surface of the cavity ,

F_{v p} true(r_{i} true) = - f_{normalh} {true \sum}_{m = 1}^{N_{normalh}} \frac{n_{m} + 1}{r} \times {[\frac{\frac{K_{1} (r)}{K_{0} (r)}}{\frac{r}{2 λ} + \frac{K_{1} (r)}{K_{0} (r)}}]}^{2} {true \overset{r}{true}}_{i m} .

Here, r = | r i − r m |/ λ and

{true \overset{r}{true}}_{i m}

= ( r i − r...…”

Section: Modelmentioning

confidence: 99%

“…Here, r i is the position of ith vortex, f v is the unit force given by f v ¼ F 2 0 =8p 2 l 3 with F 0 being the magnetic flux quantum, N v is the number of vortices, K 1 (r/l) is a modified Bessel function, and |r i À r k | is the distance between the vortices i and k. The vortex-pinning interaction is deduced from the force acting on a single vortex at the surface of the cavity [57],…”

mentioning

confidence: 99%

See 1 more Smart Citation

Strong anisotropic transport of vortices in superconductors

Yetiş

Uluer

2015

Physica Status Solidi (b)

View full text Add to dashboard Cite

Anisotropic transport of multiple vortices is investigated by a numerical simulation method in superconductors with triangular pinning arrays. The results are discussed by means of V(I) curves, structure factor, vortex flows, and velocity noise spectrum. The dynamical phase diagram as a function of the pinning strength is obtained to characterize the motion of the vortices. The results reveal the existence of a strong transport anisotropy when the multiple vortices (dimer state) are driven in two perpendicular directions. The anisotropic behavior is interpreted in terms of the triangular geometry of the pinning arrays and the nature of the competitive interactions of vortices with periodic arrays of the pinning centers. . When an ordered vortex lattice is set in motion by a transport current, its motion gives rise to a finite electrical resistance. A promising way to immobilize the vortices is to introduce artificial pinning centers, which is efficient only in a restricted range of low temperatures and magnetic fields [7].Several efforts have been devoted to stabilize vortex motion by adjusting the pinning parameters [8][9][10][11][12][13]. A rich variety of dynamical phases occurs due to the interaction of vortices with attractive pinning sites which promote disorder on the vortex lattice [14][15][16][17][18][19]. Recent experiments have shown that the vortices could display markedly different configurations, such as multiple or giant vortex states confined in mesoscopic superconducting systems [20][21][22][23][24][25][26]. Strong caging effects result in the formation of complex vortex patterns at the interstitial region of the pinning centers [27][28][29][30]. Composite vortex ordering in the presence of periodic pinning arrays is responsible for the formation of anisotropic behavior [31-33],

show abstract

“…The repulsive force between the vortices is

F_{v v} true(r_{i} true) = f_{normalv} {true \sum}_{k true(\neq i true)}^{N_{normalv}} K_{1} true(\frac{| r_{i} - r_{k} |}{λ} true) \frac{r_{i} - r_{k}}{| r_{i} - r_{k} |} .

Here, r i is the position of i th vortex, f v is the unit force given by

f_{normalv} = {normalΦ}_{0}^{2} / 8 π^{2} λ^{3}

with

{normalΦ}_{0}

F_{v p} true(r_{i} true) = - f_{normalh} {true \sum}_{m = 1}^{N_{normalh}} \frac{n_{m} + 1}{r} \times {[\frac{\frac{K_{1} (r)}{K_{0} (r)}}{\frac{r}{2 λ} + \frac{K_{1} (r)}{K_{0} (r)}}]}^{2} {true \overset{r}{true}}_{i m} .

Here, r = | r i − r m |/ λ and

{true \overset{r}{true}}_{i m}

= ( r i − r...…”

Section: Modelmentioning

confidence: 99%

mentioning

confidence: 99%

Strong anisotropic transport of vortices in superconductors

Yetiş

Uluer

2015

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…For mesoscopic samples, i.e. for a sample of the order of penetration depth, the superconducting properties such as the critical fields, the critical current, the vortex lattice and the vortex itself, can present new and very interesting properties, as for example an increase in the critical field and giant vortices carrying more than one quantum flux [1,2], the effect of defects on two and three dimensional samples on vortex configurations were studied by [5][6][7][8]. Several phenomenological theories have been developed during the decades of research in superconductivity.…”

Section: Introductionmentioning

confidence: 99%

Effect of an columnar defect on vortex configuration in a superconducting mesoscopic sample

Barba-Ortega¹,

Becerra²,

González³

2009

Braz. J. Phys.

View full text Add to dashboard Cite

In this work we investigate the vortex dynamics in a square mesoscopic superconducting cylinder in the presence of an applied magnetic field parallel to its axis. The rectangular cross-section of the sample is L 2 and an engineered columnar defect of area d 2 at the center is taken into account; L = 12ξ(0) for all simulations while d varies discretely from 1ξ(0) to 10ξ(0). We study the magnetization and the vortex configuration, increasing the magnetic field from zero to the normal state field. We found that for d ≥ 7ξ(0) no vortices in the superconductor area are possible. Also, if the size of the defect is reduced, the nucleation fields decrease.

show abstract

Direct imaging of vortex pinning at artificial antidots with different geometries

Zhang

Xue

2019

Applied Physics Letters

View full text Add to dashboard Cite

Introducing artificial antidots into superconductors is an efficient way to improve the superconducting properties for application. However, besides the pioneering theoretical studies, the fundamental question concerning how many vortices can be trapped by the antidot still needs to be further clarified from an experimental point of view. In this study, by the e-beam lithography, antidots with different sizes and shapes are fabricated in a superconducting Pb film. The vortex distribution at antidots has been directly imaged using the low-temperature scanning Hall probe microscope. A universal scaling behavior is found that the number of trapped vortices mainly depends on the size of the antidots, irrespective of the shape of antidots. The results shed light on the study of vortex pinning at artificial pinning centers, which is important for practical applications.

show abstract

Vortices in superconductors with a columnar defect: Finite size effects

Cited by 5 publications

References 12 publications

Strong anisotropic transport of vortices in superconductors

Strong anisotropic transport of vortices in superconductors

Effect of an columnar defect on vortex configuration in a superconducting mesoscopic sample

Direct imaging of vortex pinning at artificial antidots with different geometries

Contact Info

Product

Resources

About