Detecting continuous gravitational waves with superfluid 4He

S Singh, L A De Lorenzo, I Pikovski, K C Schwab
2017 New Journal of Physics  
Direct detection of gravitational waves is opening a new window onto our universe. Here, we study the sensitivity to continuous-wave strain fields of a kg-scale optomechanical system formed by the acoustic motion of superfluid helium-4 parametrically coupled to a superconducting microwave cavity. This narrowband detection scheme can operate at very high Q-factors, while the resonant frequency is tunable through pressurization of the helium in the 0.1-1.5 kHz range. The detector can therefore be
more » ... tuned to a variety of astrophysical sources and can remain sensitive to a particular source over a long period of time. For reasonable experimental parameters, we find that strain fields on the order of h∼ 10^-23 /√( Hz) are detectable. We show that the proposed system can significantly improve the limits on gravitational wave strain from nearby pulsars within a few months of integration time.
doi:10.1088/1367-2630/aa78cb fatcat:knoxm6gawfdr7fi5jjt67xou2q