Multimode quantum optomechanics with ultra-coherent nanomechanical resonators

• Published in: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) p. 1
• Main Authors: Tsaturyan, Yeghishe, Nielsen, William H. P., Moller, Christoffer B., Barg, Andreas, Junxin Chen, Seis, Yannick, Polzik, Eugene S., Schliesser, Albert
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2017
• Subjects: Optical imaging; Optical resonators; Optical sensors; Optical variables measurement; Resonators; Temperature; Temperature measurement
• DOI: 10.1109/CLEOE-EQEC.2017.8087387

We demonstrate an optomechanical system with quantum cooperativity C q = 4g 2 /κγ >> 1 already at moderate cryogenic temperature [1]. It is realised as a membrane-in-the-middle system [2] with a high-stress silicon nitride membrane. Here, y = k B T/ħQ is the quantum decoherence rate of the mechanical system due to its thermal bath at temperature T~4 K, and Q~10 7 the mechanical quality factor. In this regime, the quantum backaction of the optical measurement dominates over the thermal Langevin noise. As a consequence, optical measurements create quantum correlations between the optical and mechanical degrees of freedom, which are eventually measured as sub-vacuum noise (-2.4 dB) of the light emerging form the cavity (ponderomotive squeezing [3]). We investigate this effect in a multimode setting, in which we observe optically-induced hybridisation of mechanical modes, and the generation of squeezed light by hybrid modes [1].