Mechanical backreaction effect of the dynamical Casimir emission

Abstract

We consider an optical cavity enclosed by a freely moving mirror attached to a spring and we study the quantum friction effect exerted by the dynamical Casimir emission on the mechanical motion of the mirror. Observable signatures of this simplest example of back-reaction effect are studied in both the ring-down oscillations of the mirror motion and in its steady-state motion under a monochromatic force. Analytical expressions are found in simple yet relevant cases and compared to complete numerical solution of the master equation. A circuit-QED device allowing for experimental observation of the effect with state-of-the-art technology is proposed and theoretically characterized.

Quantum fluctuations of the friction force induced by the dynamical Casimir emission

“…Whereas this frequency shift can be viewed as a DCE analog of the Lamb shift (which is the reactive counterpart of the spontaneous radiative decay of an atom [21]), it displays an additional dependence on the amplitude b via the n a -dependence of Γ b . Whereas (11) recovers the predictions of [16] in the linear limit of small amplitudes b, a remarkable new feature is the strong nonlinearity of the equation of motion for b, which is responsible for the peculiar features of the DCE friction force as compared to standard quantum decay [17,18]. This effect is well visible in the upper plots of Fig.2(a-c) for ∆ = 0, in particular in the curves for stronger ω c values: while at late times the decay recovers the linear rate γ eff b , at early times the rate is significant faster due to the significant amount of DCE photons that are present in the cavity mode n a > 1 and stimulate the friction according to the n a -dependence of Γ b predicted by Eq.11.…”

“…From a physical point of view, the accuracy of the reformulation in terms of the stochastic TWA equations confirms our interpretation of the numerical master equation results in terms of phase diffusion: the quantum fluctuations due to the stochastic noise term dW are responsible for a wide distribution of the cavity field amplitude A(t) around its average value. Because of the nonlinear form of the motion equations (16)(17), this results in a fluctuating frequency of the mirror oscillations analogous to (11).…”

Fifty Years of the Dynamical Casimir Effect

“…Note that a simplified version of (44),Ĥ int =hG b +b † â †â , was used to describe the ponderomotive effects of a strong laser field in cavities with oscillating walls, but under the condition that the mechanical oscillator frequency is many orders of magnitude smaller than the cavity frequency, so that the DCE is negligible [142][143][144][145]. The recent progress in studies of such fully quantized optomechanical systems in connection with the DCE can be seen in [146][147][148][149][150][151][152].…”

Conversion of mechanical noise into correlated photon pairs: Dynamical Casimir effect from an incoherent mechanical drive

“…[44] also extends the investigation of the DCE to the optomechanical ultrastrong-coupling (USC) regime, where the optomechanical coupling rate is comparable to the mechanical frequency [47][48][49][50][51][52][53]. This regime, which attracted great interest also in cavity QED giving rise to a great variety of novel quantum effects [20,[54][55][56], turned out to be an essential feature for the realization of new interesting proposals in quantum optomechanics [57][58][59].…”