Andreev bound states at spin-active interfaces.

Andreev bound states are ubiquitous in superconducting hybrid structures. They are formed near impurities, in Josephson junctions, in vortex cores and at interfaces. At spin-active superconductor-ferromagnet interfaces, Andreev bound states are formed due to spin-dependent scattering phases. Spin-dependent phase shifts are an important ingredient for the generation of triplet Cooper pairs in superconductor-ferromagnet hybrid structures. Spectroscopy of Andreev bound states is a powerful probe of superconducting order parameter symmetry, as well as spin-dependent interface scattering and the triplet proximity effect.This article is part of the theme issue 'Andreev bound states'.