IQIM Postdoctoral and Graduate Student Seminar
I will discuss recent results in which we couple the low loss acoustic motion of superfluid He-4 to a high Q, superconducting niobium TE011 microwave resonator, forming a gram-scale, sideband resolved, optomechanical system. We demonstrate the detection of a series of acoustic modes with quality factors as high as 3*10^7. At higher temperatures, the lowest dissipation modes are limited by an intrinsic three phonon process. Acoustic quality factors approaching 10^11 may be possible in isotopically purified samples at temperatures below 10 mK. A system of this type may be utilized to study macroscopic quantized motion and as a frequency tunable, ultra-sensitive sensor of extremely weak displacements and forces, such as continuous gravity wave sources. I will outline the requirements of the optomechanical structure and the microwave field required for these experiments.
Ref: L. A. De Lorenzo & K. C. Schwab, New J. Phys. 16, 113020 (2014)
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