Theory of Andreev Bound States in S-F-S Junctions and S-F Proximity Devices

Abstract

Andreev bound states are an expression of quantum coherence between particles and holes in hybrid structures composed of superconducting and non-superconducting metallic parts. Their spectrum carries important information on the nature of the pairing, and determines the current in Josephson devices. Here I give a short review on Andreev bound states in systems involving superconductors and ferromagnets with strong spin-polarization. I show how the processes of spin-dependent scattering phase shifts and of triplet rotation influence Andreev point contact spectra, and provide a general framework for non-local Andreev phenomena in such structures in terms of coherence functions. Finally, I demonstrate how the concept of coherence functions cross-links wave-function and Green-function based theories, by showing that coherence functions fulfilling the equations of motion for quasiclassical Green functions can be used to derive a set of generalised Andreev equations.

27 pages, 9 figures

References in corpus (27)

• Spin Transfer Torques
• Superconducting Spintronics
• Spin-polarized supercurrents for spintronics: a review of current progress
• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Symmetries of Pairing Correlations in Superconductor-Ferromagnet Nanostructures
• Nonlocal Thermoelectric Effects and Nonlocal Onsager Relations in a Three-Terminal Proximity-Coupled Superconductor-Ferromagnet Device
• Phase controlled superconducting proximity effect probed by tunneling spectroscopy
• Observation of thermoelectric currents in high-field superconductor-ferromagnet tunnel junctions
• Spin-dependent Cooper Pair Phase and Pure Spin Supercurrents in Strongly Polarized Ferromagnets
• Manifestation of the odd-frequency spin-triplet pairing state in diffusive ferromagnet / superconductor junctions
• General Boundary Conditions for Quasiclassical Theory of Superconductivity in the Diffusive Limit: Application to Strongly Spin-polarized Systems
• Pairing symmetry conversion by spin-active interfaces in superconducting junctions
• Sign of the crossed conductances at a FSF double interface
• Spin Supercurrent, Magnetization Dynamics, and Phi-State in Spin-Textured Josephson Junctions
• Nonlocal Andreev reflection at high transmissions
• Remotely induced magnetism in a normal metal using a superconducting spin-valve
• Spin-polarized quasiparticle transport in exchange-split superconducting aluminum on europium sulfide
• Theory of Nonequilibrium Spin Transport and Spin Transfer Torque in Superconducting-Ferromagnetic Nanostructures
• Josephson current and Andreev states in superconductor-half metal-superconductor heterostructures
• Is CrO${}_2$ Fully Spin-Polarized? - Analysis of Andreev Spectra and Excess Current
• General framework for transport in spin-orbit-coupled superconducting heterostructures: Nonuniform spin-orbit coupling and spin-orbit-active interfaces
• Spin polarization of (Ga,Mn)As measured by Andreev Spectroscopy: The role of spin-active scattering
• Conductance and current noise of a superconductor/ferromagnet quantum point contact
• Dynamics of spin transport in voltage-biased Josephson junctions
• Nonlocal conductance via overlapping Andreev bound states in ferromagnet-superconductor heterostructures
• Finite frequency noise of a superconductor/ferromagnet quantum point contact
• Non-local spin-sensitive electron transport in diffusive proximity heterostructures

Cited by in corpus (9)

• Andreev Bound States and Their Signatures
• Locking of magnetization and Josephson oscillations at ferromagnetic resonance in ${\phi }_0$ junction under external radiation
• The inverse proximity effect in strong ferromagnet-superconductor structures
• Phase Crystals
• Superconductivity-enhanced spin pumping: Role of Andreev resonances
• Anomalous inverse proximity effect in unconventional-superconductor junctions
• Multiple Andreev reflections in two-dimensional Josephson junctions with broken time-reversal symmetry
• Subgap states and quantum phase transitions in one-dimensional superconductor-ferromagnetic insulator heterostructures
• Giant oscillatory Gilbert damping in superconductor/ferromagnet/superconductor junctions