Abstract
The ac Josephson effect in a ferromagnetic Josephson junction, which is composed of two superconductors separated by a ferromagnetic metal (FM), is studied by a tunneling Hamiltonian and Green's function method. We obtain two types of superconducting phase dependent currents, i.e., Josephson current and quasiparticle-pair-interference current (QPIC). These currents change their signs with thickness of the FM layer due to the 0-π transition characteristic to the ferromagnetic Josephson junction. As a function of applied voltage, the Josephson critical current shows a logarithmic divergence called the Riedel peak at the gap voltage, while the QPIC shows a discontinuous jump. The Riedel peak reverses due to the 0-π transition and disappears near the 0-π transition point. The discontinuous jump in the QPIC also represents similar behaviors to the Riedel peak. These results are in contrast to the conventional ones.
Original language | English |
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Article number | 014708 |
Journal | journal of the physical society of japan |
Volume | 78 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2009 Jan |
Keywords
- 0-state
- Ac Josephson effect
- Ferromagnet
- Ferromagnetic Josephson junction
- Pi-state
- Riedel peak
- Superconductor
ASJC Scopus subject areas
- Physics and Astronomy(all)