Transport through superconductor/magnetic dot/superconductor structures

Abstract

The coupling of two s-wave superconductors through a small magnetic dot is discussed. Assuming that the dot charging energy is small compared to the superconducting gap, $E_c\ll \Delta$, and that the moment of the dot is classical, we develop a simple theory of transport through the dot. The presence of the magnetic dot will position Andreev bound states within the superconducting gap at energies tunable with the magnetic properties of the dot. Studying the Josephson coupling it is shown that the constructed junction can be tuned from a "0" to a "$\pi$"-junction via a degenerate two-level state either by changing the magnetic moment of the dot or by changing temperature. Furthermore, it is shown that details of the magnetic dot can be extracted from the sub-harmonic structure in the current-voltage characteristics of the junction.

5 pages, 4 figures, paper presented at the conference SDP 2001 in Tokyo on June 25

References in corpus (1)

• Quasiclassical description of transport through superconducting contacts

Cited by in corpus (11)

• Proximity effects in superconductor-ferromagnet heterostructures
• Nonequilibrium Superconductivity near Spin Active Interfaces
• pi-Junction behavior and Andreev bound states in Kondo quantum dots with superconducting leads
• Ac Josephson Effect in Topological Josephson Junctions
• Theory of Nonequilibrium Spin Transport and Spin Transfer Torque in Superconducting-Ferromagnetic Nanostructures
• Non-equilibrium effects in a Josephson junction coupled to a precessing spin
• Dynamics of spin transport in voltage-biased Josephson junctions
• Spin-polarized Shapiro steps and spin-precession-assisted multiple Andreev reflection
• Subharmonic Gap Structure in Superconductor/Ferromagnet/Superconductor Junctions
• Nonequilibrium Transport in Superconductor/Ferromagnet/Superconductor Diffusive Junctions: Interplay between Proximity Effect and Ferromagnetism
• Influence of spin filtering and spin mixing on the subgap structure of I-V characteristics in superconducting quantum point contact