Coherent multiple Andreev reflections and current resonances in SNS quantum point contacts

Journal article, 2001

We study coherent multiple Andreev reflections in ballistic superconductor-normal conductor-superconductor junctions with a quantum point contact in the normal region of the junction (superconductor-normal region-quantum point contact-normal region-superconductor) with arbitrary transparency. The presence of superconducting bound states in these junctions gives rise to great enhancement of the subgap current. The effect is most pronounced in low-transparency junctions, D≪1, and in the interval of applied voltage Δ/2