Anomalous optical bistability and robust entanglement of mechanical oscillators

F. A. Hopf, Pierre Meystre, P. D. Drummond +1 more

Eyob Alebachew Sete, Hichem Eleuch

We analyze the optical bistability and the entanglement of two movable mirrors coupled to a two-mode laser in a doubly resonant cavity. We show that in stark contrast to the usual red-detuned condition for observing bistability in single-mode optomechanics, the optical intensities exhibit bistability for all values of cavity laser detuning due to intermode coupling induced by two-photon atomic coherence. Interestingly, an unconventional bistability with “ribbon”-shaped hysteresis can be observed for a certain range of cavity laser detuning. We also demonstrate that the atomic coherence leads to a strong entanglement between the movable mirrors in the adiabatic regime. Surprisingly, the mirror–mirror entanglement is shown to persist for environment temperatures of the phonon bath up to 12 K using experimental parameters.

郭永宾 Guo Yongbin, Yin Xiao, 於亚飞 Yu Yafei +1 more

Mark C. Kuzyk, S. J. van Enk, Hailin Wang

A pulsed scheme for generating robust optical entanglement via the coupling of two optical modes to a mechanical oscillator is proposed. This scheme is inspired by the S\o{}rensen-M\o{}lmer approach for entangling trapped ions in a thermal environment and is based on the use of optical driving pulses that are slightly detuned from the respective sideband resonance. We show that for certain pulse durations, the optomechanical interaction can return the mechanical oscillator to its initial state, disentangling the mechanical and optical systems. The corresponding optical entanglement generation is robust against thermal mechanical noise in the weak as well as the strong-coupling regimes. Significant optical entanglement can be generated in the weak-coupling regime, even in the presence of a large thermal phonon occupation.

Vajihe S. Mousavi, Mehdi Abdi, Mohammad Vahedi

Bijita Sarma, Amarendra K. Sarma

We investigate theoretically the effect of optical feedback from a cavity containing an ultracold two level atomic ensemble, on the bistable behavior shown by mean intracavity optical field in an optomechanical cavity resonator. It turns out that the optical bistability can be controlled by tuning the frequency and power of the single driving laser as well as by varying different system parameters provided by the hybrid interaction. Significantly, even though the atomic cavity is not driven by any laser pump and there is no coupling with the mechanical oscillator directly, the intracavity optical field in the atomic cavity also exhibits bistability due to the optical coupling with the optomechanical cavity. In essence, our work emphasizes the possibility of realization of a better controllable optical switch depending on the hybrid interaction.