Josephson current and Andreev states in superconductor-half metal-superconductor heterostructures

We develop a detailed microscopic theory describing dc Josephson effect and Andreev bound states in superconducting junctions with a half metal. In such systems, the supercurrent is caused by triplet pairing states emerging due to spin-flip scattering at the interfaces between superconducting electrodes and the half metal. For sufficiently clean metals, we provide a detailed nonperturbative description of the Josephson current at arbitrary transmissions and spin-flip scattering parameters for both interfaces. Our analysis demonstrates that the behavior of both the Josephson current and Andreev bound states crucially depends on the strength of spin-flip scattering, showing a rich variety of features which can be tested in future experiments.