Resonant tunneling in short Josephson SFS junctions

Abstract

Josephson effect in short ballistic SINIS and SIFIS double-tunnel junctions, consisting of clean superconductors (S), a normal metal (N) or metallic ferromagnet (F), and insulating interfaces (I) is studied. For SINIS double-tunnel junctions, sharp peaks in the critical Josephson current as a function of the junction width result from the resonant amplification of the Andreev process when the quasi-bound states enter the superconducting gap. For SIFIS double-tunnel junctions spin split quasi-bound states partially amplify the supercurrent and trigger the transitions between 0 and $\pi$ states of the junction. Instead of the critical current reaching a peak value (which happens when the Andreev states cross the Fermi surface in SINIS junctions), a narrow dip opens up exactly at the peak due to the compensation of partial currents flowing in opposite directions. This is related to the spin polarization of Andreev states and explains the coexistence of stable and metastable 0 and $\pi$ states in the vicinity of the transition. With increased barrier transparency, the described mechanism of $0-\pi$ transitions is modified by the broadening and overlapping of quasi-bound states (transmission resonances). Temperature-induced transitions both from 0 to $\pi$ and from $\pi$ to 0 states are studied by computing the phase diagram (temperature vs. junction width) for different interfacial transparencies varying from metallic (transparent) to the tunnel limit.

References in corpus (15)

• Proximity effects in superconductor-ferromagnet heterostructures
• Coupling of two superconductors through a ferromagnet : evidence for a pi-junction
• Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction
• Superconducting pi qubit with a ferromagnetic Josephson junction
• Spontaneous supercurrent induced by ferromagnetic pi-junctions
• Tunneling Via Individual Electronic States in Ferromagnetic Nanoparticles
• Josephson effect in double-barrier superconductor-ferromagnet junctions
• Interplay of spin-discriminated Andreev bound states forming the 0-$\pi$ transition in Superconductor-Ferromagnet-Superconductor Junctions
• Reflectionless Tunneling Through a Double-Barrier NS Junction
• $\pi -0$ Transition in Superconductor-Ferromagnetic-Superconductor Junctions
• Layered ferromagnet-superconductor structures: the $\pi$ state and proximity effects
• Exchange induced ordinary reflection in a single-channel superconductor-ferromagnet-superconductor junction
• Magnetic Field Effect on the Supercurrent of an SNS junction
• Stability of $\pi$ junction configurations in ferromagnet-superconductor heterostructures
• Transitions between "$\pi$" and "0" states in superconductor -- ferromagnet -- superconductor junctions

Cited by in corpus (5)

• Semiconductor Spintronics
• Josephson coupling through ferromagnetic heterojunctions with noncollinear magnetizations
• Manipulation with Andreev states in spin active mesoscopic Josephson junctions
• Josephson effect in S/F/S junctions: spin bandwidth asymmetry vs. Stoner exchange
• Scattering by magnetic and spin-orbit impurities and the Josephson current in superconductor-ferromagnet-superconductor junctions