Pinning of spiral fluxons by giant screw dislocations in YBa_2Cu_3O_7 single crystals: Josephson analog of the fishtail effect
arXiv:1008.4723 · doi:10.1134/S0021364010010078
Abstract
By using a highly sensitive homemade AC magnetic susceptibility technique, the magnetic flux penetration has been measured in YBa_2Cu_3O_7 single crystals with giant screw dislocations (having the structure of the Archimedean spirals) exhibiting a=3 spiral turnings, the pitch b=18.7 microns and the step height c=1.2nm (the last parameter is responsible for creation of extended weak-link structure around the giant defects). The magnetic field applied parallel to the surface enters winding around the weak-link regions of the screw in the form of the so-called spiral Josephson fluxons characterized by the temperature dependent pitch b_f(T). For a given temperature, a stabilization of the fluxon structure occurs when b_f(T) matches b (meaning an optimal pinning by the screw dislocations) and manifests itself as a pronounced low-field peak in the dependence of the susceptibility on magnetic field (applied normally to the surface) in the form resembling the high-field (Abrikosov) fishtail effect.
arXiv commentsee also http://www.jetpletters.ac.ru/ps/1886/article_28701.shtml
References in corpus (5)
- Manifestation of geometric quantization effects in temperature behavior of AC magnetic response of Josephson Junction Arrays
- Peak effect in YBCO crystals: Statics and dynamics of the vortex lattice
- Dynamical reentrance and geometry imposed quantization effects in Nb-AlOx-Nb Josephson junction arrays
- Unusually strong coherent response from grain-boundary Josephson network in polycrystalline Pr_{x}Y_{1-x}Ba_2Cu_3O_7
- Chemomagnetism, magnetoconcentration effect and "fishtail" anomaly in chemically-induced granular superconductors