Detection of the rotation of the earth with a superfluid gyrometer

The effect of the rotation of the Earth, Omega(+), on a superfluid resonator equipped with a 4.0 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(+) is measured to better than 1%, and the north direction to +/-0.5 degrees for a 10 h observation time. This experiment is the superfluid counterpart of interferometric measurements based on the Sagnac effect.