Interference phenomena in the photon production between two oscillating walls
We study the photon production in a 1D cavity whose left and right walls oscillate with the frequency $Ω_{L} $ and $Ω_{R} $, respectively. For $Ω_{L} \neq Ω_{R}, $ the number of generated photons by the parametric resonance is the sum of the photon numbers produced when the left and the right wall oscillates separately. But for $Ω_{L} = Ω_{R} $, the interference term proportional to $\cos ϕ$ is found additionally, where $ϕ$ is the phase difference between two oscillations of the walls.