Resonant charge and spin transport in a t-stub coupled to a superconductor

We study transport through a single channel t-stub geometry strongly coupled to a superconducting reservoir. In contrast to the standard stub geometry which has both transmission resonances and anti-resonances in the coherent limit, we find that due to the proximity effect, this geometry shows neither a T=1 resonance (T is the transmission probability for electrons incident on the t-stub) nor a T=0 anti-resonance as we vary the energy of the incident electron. Instead, we find that there is only one resonant value at T=1/4, where charge transport vanishes while the spin transport is perfect.Comment: This is the published versio