  Phase dynamics has been measured in a driven mesoscopic Josephson oscillator
where the resonance is tuned either by magnetic flux or by gate charge
modulation of the Josephson inductance. Phenomena are analyzed in terms of a
"phase particle picture", and by numerical circuit simulations. An analogy to
switching of a DC-biased junction into voltage state is discussed. Operation
principle of the recently demonstrated Inductive Single-Electron transistor
(L-SET) based on the driven oscillator is reviewed. The obtained charge
sensitivity implies that a performance comparable to the best rf-SETs has
already been reached with the novel device.
