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Stroboscopic phenomena in superconductors with dynamic pinning landscape.

Jelić ŽL, Milošević MV, Van de Vondel J, Silhanek AV - Sci Rep (2015)

Bottom Line: The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics.All features are tunable by the frequency of the dynamic pinning landscape.These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities.

View Article: PubMed Central - PubMed

Affiliation: Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium.

ABSTRACT
Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation. In case of spatially periodic pinning, a clear enhancement of the superconducting critical current arises when commensurability between the vortex configurations and the pinning landscape occurs. With recent achievements in (ultrafast) optics and nanoengineered plasmonics it has become possible to exploit the interaction of light with superconductivity, and create not only spatially periodic imprints on the superconducting condensate, but also temporally periodic ones. Here we show that in the latter case, temporal matching phenomena develop, caused by stroboscopic commensurability between the characteristic frequency of the vortex motion under applied current and the frequency of the dynamic pinning. The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics. All features are tunable by the frequency of the dynamic pinning landscape. These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities.

No MeSH data available.


Related in: MedlinePlus

Shapiro steps.(a) The Shapiro steps in V(j) characteristics for the pinning period of . V0 indicates the Shapiro step at first resonance. (b) The resonant behavior in V(τ) for different values of magnetic field indicates possible Shapiro steps in magnetoresistivity. (c) The resonant behavior in V(τ) is also found for varied disorder, i.e. varied inelastic phonon-electron scattering time, with effective influence on the viscosity of the superconducting condensate (parameter γ in the theory, see Methods).
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f4: Shapiro steps.(a) The Shapiro steps in V(j) characteristics for the pinning period of . V0 indicates the Shapiro step at first resonance. (b) The resonant behavior in V(τ) for different values of magnetic field indicates possible Shapiro steps in magnetoresistivity. (c) The resonant behavior in V(τ) is also found for varied disorder, i.e. varied inelastic phonon-electron scattering time, with effective influence on the viscosity of the superconducting condensate (parameter γ in the theory, see Methods).

Mentions: Another careful look at the resonances shown in Fig. 2 reveals more important details. Particularly, we observe that voltage curves obtained for different currents can overlap at certain pinning periods. In other words, for specific τ the system can exhibit identical voltage at two different bias currents. One of such cases is examined in Fig. 4, where we constructed the current-voltage J–V characteristics for . For J = 0.062 − 0.066j0 the system remains in the same n = 1 resonance, as seen in Fig. 2, and consequently J–V characteristics show a Shapiro step at these currents. At larger currents more Shapiro steps are found, corresponding to higher resonances and exhibiting exactly quantized voltages—equal to nV0, thus tunable by τ.


Stroboscopic phenomena in superconductors with dynamic pinning landscape.

Jelić ŽL, Milošević MV, Van de Vondel J, Silhanek AV - Sci Rep (2015)

Shapiro steps.(a) The Shapiro steps in V(j) characteristics for the pinning period of . V0 indicates the Shapiro step at first resonance. (b) The resonant behavior in V(τ) for different values of magnetic field indicates possible Shapiro steps in magnetoresistivity. (c) The resonant behavior in V(τ) is also found for varied disorder, i.e. varied inelastic phonon-electron scattering time, with effective influence on the viscosity of the superconducting condensate (parameter γ in the theory, see Methods).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589687&req=5

f4: Shapiro steps.(a) The Shapiro steps in V(j) characteristics for the pinning period of . V0 indicates the Shapiro step at first resonance. (b) The resonant behavior in V(τ) for different values of magnetic field indicates possible Shapiro steps in magnetoresistivity. (c) The resonant behavior in V(τ) is also found for varied disorder, i.e. varied inelastic phonon-electron scattering time, with effective influence on the viscosity of the superconducting condensate (parameter γ in the theory, see Methods).
Mentions: Another careful look at the resonances shown in Fig. 2 reveals more important details. Particularly, we observe that voltage curves obtained for different currents can overlap at certain pinning periods. In other words, for specific τ the system can exhibit identical voltage at two different bias currents. One of such cases is examined in Fig. 4, where we constructed the current-voltage J–V characteristics for . For J = 0.062 − 0.066j0 the system remains in the same n = 1 resonance, as seen in Fig. 2, and consequently J–V characteristics show a Shapiro step at these currents. At larger currents more Shapiro steps are found, corresponding to higher resonances and exhibiting exactly quantized voltages—equal to nV0, thus tunable by τ.

Bottom Line: The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics.All features are tunable by the frequency of the dynamic pinning landscape.These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities.

View Article: PubMed Central - PubMed

Affiliation: Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium.

ABSTRACT
Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation. In case of spatially periodic pinning, a clear enhancement of the superconducting critical current arises when commensurability between the vortex configurations and the pinning landscape occurs. With recent achievements in (ultrafast) optics and nanoengineered plasmonics it has become possible to exploit the interaction of light with superconductivity, and create not only spatially periodic imprints on the superconducting condensate, but also temporally periodic ones. Here we show that in the latter case, temporal matching phenomena develop, caused by stroboscopic commensurability between the characteristic frequency of the vortex motion under applied current and the frequency of the dynamic pinning. The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics. All features are tunable by the frequency of the dynamic pinning landscape. These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities.

No MeSH data available.


Related in: MedlinePlus