A fully quantum analysis of the dynamical Casimir effect
By rapidly changing a boundary condition for the electromagnetic field, e.g., by moving a mirror very quickly, fluctuations in the quantum vacuum can be converted into real photons. This is known as the dynamical Casimir effect, the first experimental demonstration of which was realized only a few years ago, using superconducting circuits. In most theoretical studies treating the dynamical Casimir effect, the trajectory of the mirror is classical. In this work, we instead use a fully quantum-mechanical description of both the cavity field and the oscillating mirror in an optomechanical setup (see the figure). By numerically diagonalizing the full optomechanical Hamiltonian, we show that the resonant generation of photons from the vacuum is determined by mirror-field Rabi splittings, and that vacuum Casimir-Rabi oscillations can occur. We also find that, for strong optomechanical coupling, a resonant production of photons out from the vacuum can be observed even for mechanical frequencies below the cavity frequency if the mirror is coherently driven. Since high mechanical frequencies, which are hard to achieve experimentally, were thought to be imperative for realizing the dynamical Casimir effect, this result removes a major obstacle for its experimental observation in a conventional optomechanical setup.
Nonperturbative dynamical Casimir effect in optomechanical systems: vacuum Casimir-Rabi splittings
Vincenzo Macrì, Alessandro Ridolfo, Omar Di Stefano, Anton Frisk Kockum, Franco Nori, and Salvatore Savasta
arXiv:1706.04134
