Order in driven vortex lattices in superconducting Nb films with nanostructured pinning potentials

Vélez, María; Jaque, D.; Martín, José Ignacio; Guinea, F.; Vicent, J. L.

doi:10.1103/physrevb.65.094509

Cited by 35 publications

(51 citation statements)

References 25 publications

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“…The details of the NbN film used for fabricating the triangular antidot array is shown in Table 1 line lattices [5][6][7]. Simulations on triangular antidot array by Reichhardt et al [17] corroborate this scenario.…”

Section: Resultssupporting

confidence: 64%

“…Horng et al [4] demonstrated the absence of certain matching periods in the case when interstitial vortices nucleate in the antidot array samples. Furthermore, there exists experimental evidence for a possible reordering of the nucleated interstitial vortices leading to a "super matching (SL)" flux line lattices [5][6][7]. Within the theoretical scenario proposed by Mkrtchyan and Shmidt [8], the maximum number of vortices captured by an isolated antidot (columnar defect) of diameter D is given by the saturation number (n s ) where, [9].…”

Section: Introductionmentioning

confidence: 99%

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Multi-vortex versus interstitial vortices scenario in superconducting antidot arrays

Thakur¹,

Ooi²,

Chockalingam³

et al. 2010

Physica C: Superconductivity and its Applications

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In superconducting thin films, engineered lattice of antidots (holes) act as an array of columnar pinning sites for the vortices and thus lead to vortex matching phenomena at commensurate fields guided by the lattice spacing. The strength and nature of vortex pinning is determined by the geometrical characteristics of the antidot lattice (such as the lattice spacing a 0 , antidot diameter d, lattice symmetry, orientation, etc) along with the characteristic length scales of the superconducting thin films, viz., the coherence length (ξ) and the penetration depth (λ). There are at least two competing scenarios: (i) multiple vortices sit on each of the antidots at a higher matching period, and, (ii) there is nucleation of vortices at the interstitial sites at higher matching periods. Furthermore it is also possible for the nucleated interstitial vortices to reorder under suitable conditions. We present our experimental results on NbN antidot arrays in the light of the above scenarios.2

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Section: Resultssupporting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Multi-vortex versus interstitial vortices scenario in superconducting antidot arrays

Thakur¹,

Ooi²,

Chockalingam³

et al. 2010

Physica C: Superconductivity and its Applications

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“…This has allowed experimental exploration of many phenomena regarding static and dynamic properties of the VL. The most remarkable effects arising in this kind of nanostructured superconductors include commensurability between the VL and the periodic array of pinning centers, [2][3][4][5][6][7][8][9][10][11][12] competition between random and periodic pinning, 13 channeling effects in the VL dynamics, 14 or the ratchet effect. 15 Interestingly, much of the physics related to VL dynamics on periodic pinning potentials might apply to other systems in which transport of small particles takes place through fixed periodic potentials, as for instance colloids, 16 electrons in periodic antidot arrays, 17 etc.…”

Section: Introductionmentioning

confidence: 99%

Vortex-lattice dynamics with channeled pinning potential landscapes

et al. 2005

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We have studied vortex-lattice dynamics as a function of driving force direction, in superconducting Nb films with periodic pinning arrays of magnetic dots. Square and rectangular symmetry arrays define channels that guide the vortex-lattice motion. We investigated the effect of the driving force direction on the commensurability between the vortex-lattice and dots array. We also studied the transverse depinning of the vortexlattice as is moving longitudinally along channels. We found that transverse depinning forces are enhanced with respect to the static situation. The results are discussed in terms of the dynamical evolution of order in the vortex-lattice.

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“…Below a threshold current value the vortex lattice velocity is too low and the intrinsic and random potentials overcome the periodic pinning, therefore the periodic pinning effect vanishes; above a second threshold current value ͑high driving force͒ the vortex lattice velocity is enhanced and the vortex lattice does not undergo the periodic potentials. 13 The competition between the vortex-vortex interaction and the asymmetric potentials could be explored by increasing the applied magnetic field, which means more vortices per array unit cell. Figure 3 shows ratchet and transverse effects when the number of vortices increase to 4 ͓Fig.…”

mentioning

confidence: 99%

“…The suitable temperatures and driving forces for exploring ratchet and matching effects have been discussed elsewhere. 6,13 In summary, the temperature should be very close to the superconducting critical temperature and the driving forces ͑currents͒ should be between the two current values. Below a threshold current value the vortex lattice velocity is too low and the intrinsic and random potentials overcome the periodic pinning, therefore the periodic pinning effect vanishes; above a second threshold current value ͑high driving force͒ the vortex lattice velocity is enhanced and the vortex lattice does not undergo the periodic potentials.…”

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confidence: 99%

Transverse rectification in superconducting thin films with arrays of asymmetric defects

González

Núñez

Anguita³

et al. 2007

Applied Physics Letters

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Superconducting Nb films have been grown on top of arrays of Cu nanotriangles. These asymmetric pinning centers strongly modify the vortex lattice dynamics. Two rectification effects have been observed: ͑i͒ longitudinal ratchet effect when the input currents are injected perpendicular to the triangle reflection symmetry axis and ͑ii͒ transverse rectification effect when the input currents are injected parallel to the triangle reflection symmetry axis and the output voltage drop occurs perpendicular to the triangle reflection symmetry axis. Increasing the applied magnetic field, the former shows a change of the output voltage polarity, the transverse output voltage does not show any polarity reversal. © 2007 American Institute of Physics. ͓DOI: 10.1063/1.2767199͔Arrays of nanodefects embedded in superconducting thin films are a powerful tool to control the vortex lattice motion. Superconducting films fabricated on arrays of periodic and symmetric pinning potentials show, for instance, vortex lattice channeling effects 1 that allows us to guide the vortex lattice motion. Superconducting films with arrays of periodic and asymmetric pinning centers show vortex motion rectification effects. 2 This rectification is based on the ratchet effect, that, is the net motion of particles induced by asymmetric potentials, without the need of being driven by nonzero average forces or temperature gradients. 3 This vortex ratchet effect could be used for improving the performance of existing superconducting devices, for instance, diminishing the noise in superconducting quantum interference devices coming from trapped magnetic flux as has been proposed by Lee et al. 4 Furthermore, the vortex ratchet effect shows very interesting properties; for example, the output signal polarity could be tuned with external parameters ͑for instance, applied magnetic fields͒. 2,5 Moreover, this vortex ratchet is an adiabatic ratchet; i.e., the effect shows a nonfrequency dependence that allows us to study and mimic the vortex ratchet effect by I͑V͒ curves. 6,7 The possible transverse rectification of particles has been theoretically studied by several authors. 8,9 The transverse ratchet effect for vortices moving in arrays of triangular pinning sites was specifically studied by Reichhardt-Olson and Reichhardt. 10 The transverse effect could be used for fabricating devices whose aim should be particle separation ͑DNA sorting, ion channeling, and so on͒. In this letter, we will deal with transverse and ratchet rectifier devices based on Nb films grown on top of an array of Cu nanotriangles. We will experimentally show that the same device could exhibit longitudinal ratchet rectification and transverse ratchet rectification. In the longitudinal ratchet configuration the driving current is applied perpendicular to the triangle reflection symmetry axis ͑tip to base axis͒ and the output voltage signal is recorded on the same direction. The Lorentz force induces vortex motion parallel to the triangle reflection symmetry axis, but the output ͑dissipati...

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Order in driven vortex lattices in superconducting Nb films with nanostructured pinning potentials

Cited by 35 publications

References 25 publications

Multi-vortex versus interstitial vortices scenario in superconducting antidot arrays

Multi-vortex versus interstitial vortices scenario in superconducting antidot arrays

Vortex-lattice dynamics with channeled pinning potential landscapes

Transverse rectification in superconducting thin films with arrays of asymmetric defects

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