Pinning of spiral fluxons by giant screw dislocations in YBa_2Cu_3O_7 single crystals: Josephson analog of the fishtail effect
| Autor: | Sergeenkov, S., Cichetto, L. Jr., Rivera, V. A. G., Stari, C., Marega, E., Cardoso, C. A., Araujo-Moreira, F. M. |
|---|---|
| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | JETP Letters 91, 30 (2010) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1134/S0021364010010078 |
| Popis: | 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. Comment: see also http://www.jetpletters.ac.ru/ps/1886/article_28701.shtml |
| Databáze: | arXiv |
| Externí odkaz: |
|