Andreev levels of SNS-junctions in weak magnetic fields

Abstract

Spatial quantization of the energy spectrum of quasiparticles, bound by Andreev scattering in the normal layer of SNS junctions, remains observable in weak constant magnetic fieldsH _‖ parallel to the phase boundaries. Quasiparticles, especially in the low lying Andreev states, can traverse thick normal regions many thousand times before they are scattered once by interaction withH _‖. This confirms the expectation that quasiparticle transport phenomena in superconducting heterostructures should be little influenced by magnetic fields as long as the cyclotron radius greatly exceeds the average spatial extension of the unperturbed wave functions normal to the phase boundaries.