Photo-assisted Andreev reflection as a probe of quantum noise
Résumé
Andreev reflection, which corresponds to the tunneling of two electrons from a metallic lead to a superconductor lead as a Cooper pair (or vice versa), can be exploited to measure high frequency noise. A detector is proposed, which consists of a normal lead--quantum dot--superconductor circuit, which is capacitively coupled to a mesoscopic circuit where noise is to be measured. A substantial DC current can flow in the detector circuit only if an appropriate photon is provided or absorbed by the mesoscopic circuit, which plays the role of an environment for the dot-superconductor junction.