Science – Future of Lithuania / Mokslas – Lietuvos Ateitis, Vol 3, No 6 (2011)

Coherent Vortex Motion in Yba2cu3o7-Z Superconducting Thin Films Containing Π-Shaped Channel for Easy Vortex Motion Biased at I ~ IC

Lina Steponavičienė
Artūras Jukna


The current vs. voltage dependences of YBa2Cu3O7-x superconducting microbridges containing laser–written (LW) -shaped channel for easy vortex motion have been investigated in a narrow range of temperatures ranging from 87.3 to 88.6 K that are still below the critical temperature Tc of the material. In the range of the before mentioned temperatures the current-self magnetic field produced, Abrikosov magnetic vortices/anti-vortices appear in the partially deoxygenated (x ~ 0.2) channel and move coherently identifying itself as Josephson–like voltage “steps” in nonlinear current–voltage dependences. Bias current creates Lorentz force FL, pushing vortices along the LW-channel from its edges towards the centre. As follows from current-voltage dependences, vortices start moving at I = Ic. This current satisfies condition FL >> Fp (where Fp – is pinning force in the film). Our results confirm that oxygen vacancies in the channel area decrease the pinning force of screw-dislocations and make the channel of uniform pinning. Then, even at I = Ic, Abrikosov magnetic vortices create a spontaneous channel in the deoxygenated channel of the superconducting microbridge and start moving coherently.

Article in Lithuanian

Article in: Lithuanian

Article published: 2012-01-03

Keyword(s): II-type superconductor, thin film, critical magnetic field, vortex channel, coherence length, pinning force, pining center, Lorentz force

DOI: 10.3846/mla.2011.123

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Science – Future of Lithuania / Mokslas – Lietuvos Ateitis ISSN 2029-2341, eISSN 2029-2252
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