Magnetinių sūkurių superlaidžiame sluosnyje valdymas

Abstract

Pronounced random telegraph noise signals have been observed in voltages measured across current-biased, 0.3-//m-thick, epitaxial, thin-film, YBa2Cu307.6 superconducting 50 xlOO um2 microbridges, containing laser-processed, 5-Iim-wide channels for easy vortex motion. The superconductivity along the laser illuminated path is not destroyed, only depressed. Partial oxygen depletion from the channel area effectively reduced the strength of the dominant extended pinning sites created favorable conditions for the onset of vortex motion at currents much lower than the critical current of the pristine (channel-free) bridge. The appearance of one- and two-levels telegraph noise in bridges with single and double laser-written channels, respectively, is interpreted as experimental evidence that intermittent channeled vortex flow may be responsible for generation of the random telegraph noise signals in type-II superconductors.