The observation of the photoelectric effect at the beginning of the previous century played a crucial role in Einstein’s reasoning that lead him to postulate the existence of the photon in 1905. Paradoxically, in our modern interpretation of this effect, the incoming light that ejects the electron may often be treated classically and photons do not appear in the calculation. The photoassisted tunneling of an electron through a metallic tunnel junction is a direct analogue to the photoelectric effect. When the photon absorbed by the electron comes from a high impedance microwave mode, one arrives at a rare situation where, both the electron and the photon, must be treated quantum mechanically. After reviewing these effects, I will present some results from a microwave quantum optics experiment based on such photoassisted tunneling in the quantum regime.

Coffee and pastries will be served at 11:00 in the hall.