  We consider a three-terminal system consisting of a quantum dot strongly
coupled to two superconducting reservoirs in the infinite gap limit and weakly
coupled to a normal metal. Using a real-time diagrammatic approach, we
calculate the dynamics of the proximity-induced pair amplitude on the quantum
dot. We find that after a quench the pair amplitude shows pronounced
oscillations with a frequency determined by the coupling to the
superconductors. In addition, it decays exponentially on a time scale set by
the coupling to the normal metal. Strong oscillations of the pair amplitude
occur also when the system is periodically driven both in the adiabatic and
fast-driving limit. We relate the dynamics of the pair amplitude to the
Josephson and Andreev current through the dot to demonstrate that it is an
experimentally accessible quantity.

Mesoscale and Nanoscale Physics