Josephson Effect in SFXSF Junctions
Abstract
We investigate the Josephson effect in S$_{\rm F}$XS$_{\rm F}$ junctions, where S$_{\rm F}$ is a superconducting material with a ferromagnetic exchange field, and X a weak link. The critical current $I_c$ increases with the (antiparallel) exchange fields if the distribution of transmission eigenvalues of the X-layer has its maximum weight at small values. This exchange field enhancement of the supercurrent does not exist if X is a diffusive normal metal. At low temperatures, there is a correspondence between the critical current in an S$_{\rm F}$IS$_{\rm F}$ junction with collinear orientations of the two exchange fields, and the AC supercurrent amplitude in an SIS tunnel junction. The difference of the exchange fields $h_1-h_2$ in an S$_{\rm F}$IS$_{\rm F}$ junction corresponds to the potential difference $V_1-V_2$ in an SIS junction; i.e., the singularity in $I_c$ [in an S$_{\rm F}$IS$_{\rm F}$ junction] at $|h_1-h_2|=\Delta_1+\Delta_2$ is the analogue of the Riedel peak. We also discuss the AC Josephson effect in S$_{\rm F}$IS$_{\rm F}$ junctions.
- Publication:
-
Soviet Journal of Experimental and Theoretical Physics Letters
- Pub Date:
- June 2002
- DOI:
- 10.1134/1.1503330
- arXiv:
- arXiv:cond-mat/0205316
- Bibcode:
- 2002JETPL..75..646C
- Keywords:
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- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Superconductivity
- E-Print:
- 5 pages, 5 figures