Coherent vortex motion in Y[Ba.sub.2][Cu.sub.3][O.sub.7-Z] superconducting thin films containing Π-shaped channel for easy vortex motion biased at I ~ [I.sub.c]/Magnetiniu sukuriu koherentinio judejimo y[Ba.sub.2][Cu.sub.3][O.sub.7-x] superlaidziuosiuose plonuosiuose sluoksniuose su lazeriu suformuotu Π formos sukuriu kanalu tyrimai, sluoksniais tekant srovei I ~ [I.sub.c]

The current vs. voltage dependences of Y[Ba.sub.2][Cu.sub.3][O.sub.7-x] superconducting microbridges containing laser-written (LW) Π-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 [T.sub.c] of the material. In the range of the before mentioned temperatures the current-self magnetic field produced, Abrikosov magnetic vortices/antivortices 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 [F.sub.L], pushing vortices along the LW-channel from its edges towards the centre. As follows from current-voltage dependences, vortices start moving at I = [I.sub.c]. This current satisfies condition [F.sub.L] ≫ [F.sub.p] (where [F.sub.p]--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 = [I.sub.c], Abrikosov magnetic vortices create a spontaneous channel in the deoxygenated channel of the superconducting microbridge and start moving coherently. Keywords: II-type superconductor, thin film, critical magnetic field, vortex channel, coherence length, pinning force, pining center, Lorentz force. Darbe nagrinejami silpnai tarpusavyje saveikaujanciu Abrikosovo magnetiniu sukuriu judejimo ypatumai 0,3 µm storio, 100 µm ilgio ir 50 µm plocio Y[Ba.sub.2][Cu.sub.3][O.sub.7-x] superlaidziuosiuose dariniuose, turinciuose is dalies deguonimi nuskurdinta Π formos Abrikosovo magnetiniu sukuriu kanala. Sukuriu kanalas superlaidziajame darinyje sudarytas sufokusuotu i 5 µm skersmens deme lazerio spinduliu. Sviesos poveikiu modifikuotame superlaidziojo darinio kanale (x < 0,2) atsirado papildomi sukuriu prieraisos centrai (deguonies vakansijos), kuriu kuriama sukuriu prieraisos jega [F.sub.p] sumazino stipriu prieraisos centru kuriama prieraisos jega ir sukure palankias salygas Abrikosovo magnetiniu sukuriu judejimui, dariniu tekant srovei, kurios tankis keliomis eilemis mazesnis uz sviesa nemodifikuoto superlaidininko dalies kritini sroves tanki. Atliktu tyrimu rezultatai rodo, kad koherentinis Abrikosovo magnetiniu sukuriu judejimas superlaidininke, eksperimentuose pasireiskiantis itampos laipteliais voltamperineje darinio charakteristikoje, gali atsirasti esant [F.su