21 Mar 2025
Nicole presented on a work-in-progress about superfluid optomechanics at APS March Meeting in Anaheim, California.
Abstract
Superfluid helium has been proven to be an effective optomechanical system due to its low electromagnetic and acoustic dissipation [1]. However, its low refractive index (nHe~1.029) introduces difficulties in confining light and optimizing the co-localization between light and sound in small interaction volumes; current techniques being used to confine superfluid helium are not able to achieve subwavelength-scale interaction volumes [2]. Using integrated photonic circuitry [3], we demonstrate the ability to initialize extremely confined volumes of bulk superfluid helium co-located with high Q optical modes. For the first time, we are able to persistently trap and observe nanoscale volumes of superfluid helium. These sustain GHz first sound modes which, at millikelvin temperatures are in their motional quantum ground state. Building on recent advancements in quantum optomechanics with liquids [4], this work paves the road for the study of superfluid helium in confined volumes and roton physics [5].
References
[1] A. Kashkanova, A. Shkarin, C. Brown, N. Flowers-Jacobs, L. Childress, S. Hoch, L. Hohmann, K. Ott, J. Reichel, and J. Harris, “Superfluid brillouin optomechanics,” Nat. Phys. 13(1), 74–79 (2017).
[2] Glen I. Harris, Andreas Sawadsky, Yasmine L. Sfendla, Walter W. Wasserman, Warwick P. Bowen, and Christopher G. Baker, “Proposal for a quantum traveling Brillouin resonator,” Opt. Express 28, 22450-22461 (2020).
[3] W. W. Wasserman, R. A. Harrison, G. I. Harris, A. Sawadsky, Y. L. Sfendla, W. P. Bowen, and C. G. Baker, “Cryogenic and hermetically sealed packaging of photonic chips for optomechanics,” Opt. Express 30, 30822-30831 (2022)
[4] He, X., Harris, G.I., Baker, C.G. et al. Strong optical coupling through superfluid Brillouin lasing. Nat. Phys. 16, 417–421 (2020).
[5] V. Milner, A.A. Milner. Controlled excitation of rotons in superfluid helium with an optical centrifuge. Phys. Rev. Lett., 131:166001, Oct 2023.
