15 research outputs found

    Brillouin cavity optomechanics: Single-quantum-level operations towards quantum memory applications

    Get PDF
    Cavity-enhanced Brillouin scattering interactions with gigahertz-frequency acoustic phonons offer a promising pathway towards the quantum coherent control of mechanical oscillators. In this thesis, I experimentally investigate single-quantum-level operations applied to thermal me- chanical oscillators by combining optical measurement techniques with Brillouin interactions in crystalline whispering-gallery-mode microresonator devices. These operations are explored for applications in quantum state engineering and optical quantum memories. Generating and characterising non-classical states of mechanical motion currently represents a key challenge in quantum cavity optomechanics, and the realisation of a quantum memory would enable the development of many quantum technologies. The advances reported here contribute to both of these active areas of research. In a series of three experiments, single- and multi-phonon addition and subtraction opera- tions applied to thermal mechanical states are explored. I present the first experimental inves- tigation of single-phonon addition and subtraction operations using a joint click-dyne detection scheme, where the effect of such operations are verified by observing a characteristic doubling of the mean occupation of the state. These techniques are then extended to multi-phonon subtraction. Here, the -parameterised Wigner function of the resulting non-Gaussian states are determined, advancing the state-of-the-art for optics-based mechanical state tomography. Finally, an interferometric detection scheme is employed that implements a superposition of phonon subtractions in two time bins, and the phase coherence between these two operations is demonstrated and studied. In this thesis, I also theoretically investigate the prospects of an optical quantum memory based on Brillouin cavity optomechanics. Using realistic parameters, I show that efficient storage and retrieval of single photons is feasible, and I identify two key applications: temporal multiplexing and temporal mode manipulation. The deleterious effect of thermal noise in such optomechanical quantum light storage is also considered. To conclude, an outlook towards some near-term and long-term experimental goals that can build upon on the achievements reported is presented.Open Acces

    Hybrid photon-phonon blockade

    Full text link
    We describe a novel type of blockade in a hybrid mode generated by linear coupling of photonic and phononic modes. We refer to this effect as hybrid photon-phonon blockade and show how it can be generated and detected in a driven nonlinear optomechanical superconducting system. Thus, we study boson-number correlations in the photon, phonon, and hybrid modes in linearly coupled microwave and mechanical resonators with a superconducting qubit inserted in one of them. We find such system parameters for which we observe eight types of different combinations of either blockade or tunnelling effects (defined via the sub- and super-Poissonian statistics) for photons, phonons, and hybrid bosons. In particular, we find that the hybrid photon-phonon blockade can be generated by mixing the photonic and phononic modes which do not exhibit blockade.Comment: 20 pages, 14 figure

    Tunable phonon blockade in weakly nonlinear coupled mechanical resonators via Coulomb interaction

    Full text link
    Realizing quantum mechanical behavior in micro- and nanomechanical resonators has attracted continuous research effort. One of the ways for observing quantum nature of mechanical objects is via the mechanism of phonon blockade. Here, we show that phonon blockade could be achieved in a system of two weakly nonlinear mechanical resonators coupled by a Coulomb interaction. The optimal blockade arises as a result of the destructive quantum interference between paths leading to two-phonon excitation. It is observed that, in comparison to a single drive applied on one mechanical resonator, driving both the resonators can be beneficial in many aspects; such as, in terms of the temperature sensitivity of phonon blockade and also with regard to the tunability, by controlling the amplitude and the phase of the second drive externally. We also show that via a radiation pressure induced coupling in an optomechanical cavity, phonon correlations can be measured indirectly in terms of photon correlations of the cavity mode
    corecore