Detection of the Rotation of the Earth with a Superfluid Gyrometer

Abstract

The effect of the rotation of the Earth, ${\Omega }_{\oplus }$, on a superfluid resonator equipped with a $4.0{\mathrm{cm}}^2$ rotation pickup loop and with a microaperture is reported. The velocity circulation induced in the loop by the rotation is detected by phase-slippage techniques. The magnitude of ${\Omega }_{\oplus }$ is measured to better than 1%, and the north direction to $\pm 0.5°$ for a 10 h observation time. This experiment is the superfluid counterpart of interferometric measurements based on the Sagnac effect.