Nonstationary boundary effect for a quantum flux in superconducting nanocircuits

We investigate nonstationary boundary effect for a quantum flux in superconducting quantum nanocircuits. This is a circuit analogue of the dynamical Casimir effect in quantum field theory. We describe a scheme for producing rapidly movable ( non-material) boundaries introduced by time-dependent potential and for detecting photons out of the vacuum in the circuit. We also discuss an experimental feasibility of our approach.