Effects of geometry on quantum fluctuations of phonon-trapping acoustic cavities

    Research output: Contribution to journalArticle

    9 Citations (Scopus)
    128 Downloads (Pure)

    Abstract

    This work presents some peculiarities of the near quantum ground state behaviour of curved (phonon trapping) bulk acoustic wave (BAW) cavities when compared to a conventional mechanical resonator. The curved cavity system resolves the quandary of the conventional mechanical system where the Bose-Einstein distribution requires higher frequencies for lower quantum occupation factors contrary to the constraint of an inverse frequency dependence of the quantum fluctuations of displacement. We demonstrate how the non-trivial cavity geometry can lead to better phonon trapping, enhancing the variance of zero-point-fluctuations of displacement. This variance becomes independent of overtone (OT) number (or BAW resonance frequency) overcoming the constraint and allowing better observation of quantum effects in a mechanical system. The piezoelectric electro-mechanical coupling approach is qualitatively compared to the parametric optomechanical technique for the curved BAW cavities. In both cases the detectible quantity grows proportional to the square root of the OT number, and thus the resonance frequency. Also, the phonon trapping improves with higher OT numbers, which allows the electrode size to be reduced such that in the optimal case the parasitic capacitive impedance becomes independent of the OT number, allowing effective coupling to very high frequency OTs. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
    Original languageEnglish
    Pages (from-to)083007
    JournalNew Journal of Physics
    Volume16
    DOIs
    Publication statusPublished - 4 Aug 2014

    Fingerprint

    trapping
    harmonics
    cavities
    acoustics
    geometry
    very high frequencies
    occupation
    resonators
    impedance
    ground state
    electrodes

    Cite this

    @article{96c3ddf5a2324bc0b088cb9b6fb6831d,
    title = "Effects of geometry on quantum fluctuations of phonon-trapping acoustic cavities",
    abstract = "This work presents some peculiarities of the near quantum ground state behaviour of curved (phonon trapping) bulk acoustic wave (BAW) cavities when compared to a conventional mechanical resonator. The curved cavity system resolves the quandary of the conventional mechanical system where the Bose-Einstein distribution requires higher frequencies for lower quantum occupation factors contrary to the constraint of an inverse frequency dependence of the quantum fluctuations of displacement. We demonstrate how the non-trivial cavity geometry can lead to better phonon trapping, enhancing the variance of zero-point-fluctuations of displacement. This variance becomes independent of overtone (OT) number (or BAW resonance frequency) overcoming the constraint and allowing better observation of quantum effects in a mechanical system. The piezoelectric electro-mechanical coupling approach is qualitatively compared to the parametric optomechanical technique for the curved BAW cavities. In both cases the detectible quantity grows proportional to the square root of the OT number, and thus the resonance frequency. Also, the phonon trapping improves with higher OT numbers, which allows the electrode size to be reduced such that in the optimal case the parasitic capacitive impedance becomes independent of the OT number, allowing effective coupling to very high frequency OTs. {\circledC} 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.",
    author = "Maxim Goryachev and Michael Tobar",
    year = "2014",
    month = "8",
    day = "4",
    doi = "10.1088/1367-2630/16/8/083007",
    language = "English",
    volume = "16",
    pages = "083007",
    journal = "New Journal of Physics",
    issn = "1367-2630",
    publisher = "IOP Publishing",

    }

    Effects of geometry on quantum fluctuations of phonon-trapping acoustic cavities. / Goryachev, Maxim; Tobar, Michael.

    In: New Journal of Physics, Vol. 16, 04.08.2014, p. 083007.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Effects of geometry on quantum fluctuations of phonon-trapping acoustic cavities

    AU - Goryachev, Maxim

    AU - Tobar, Michael

    PY - 2014/8/4

    Y1 - 2014/8/4

    N2 - This work presents some peculiarities of the near quantum ground state behaviour of curved (phonon trapping) bulk acoustic wave (BAW) cavities when compared to a conventional mechanical resonator. The curved cavity system resolves the quandary of the conventional mechanical system where the Bose-Einstein distribution requires higher frequencies for lower quantum occupation factors contrary to the constraint of an inverse frequency dependence of the quantum fluctuations of displacement. We demonstrate how the non-trivial cavity geometry can lead to better phonon trapping, enhancing the variance of zero-point-fluctuations of displacement. This variance becomes independent of overtone (OT) number (or BAW resonance frequency) overcoming the constraint and allowing better observation of quantum effects in a mechanical system. The piezoelectric electro-mechanical coupling approach is qualitatively compared to the parametric optomechanical technique for the curved BAW cavities. In both cases the detectible quantity grows proportional to the square root of the OT number, and thus the resonance frequency. Also, the phonon trapping improves with higher OT numbers, which allows the electrode size to be reduced such that in the optimal case the parasitic capacitive impedance becomes independent of the OT number, allowing effective coupling to very high frequency OTs. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

    AB - This work presents some peculiarities of the near quantum ground state behaviour of curved (phonon trapping) bulk acoustic wave (BAW) cavities when compared to a conventional mechanical resonator. The curved cavity system resolves the quandary of the conventional mechanical system where the Bose-Einstein distribution requires higher frequencies for lower quantum occupation factors contrary to the constraint of an inverse frequency dependence of the quantum fluctuations of displacement. We demonstrate how the non-trivial cavity geometry can lead to better phonon trapping, enhancing the variance of zero-point-fluctuations of displacement. This variance becomes independent of overtone (OT) number (or BAW resonance frequency) overcoming the constraint and allowing better observation of quantum effects in a mechanical system. The piezoelectric electro-mechanical coupling approach is qualitatively compared to the parametric optomechanical technique for the curved BAW cavities. In both cases the detectible quantity grows proportional to the square root of the OT number, and thus the resonance frequency. Also, the phonon trapping improves with higher OT numbers, which allows the electrode size to be reduced such that in the optimal case the parasitic capacitive impedance becomes independent of the OT number, allowing effective coupling to very high frequency OTs. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

    U2 - 10.1088/1367-2630/16/8/083007

    DO - 10.1088/1367-2630/16/8/083007

    M3 - Article

    VL - 16

    SP - 083007

    JO - New Journal of Physics

    JF - New Journal of Physics

    SN - 1367-2630

    ER -