228 research outputs found
Extended Analysis of Gravitomagnetic Fields in Rotating Superconductors and Superfluids
Applying the Ginzburg-Landau theory including frame dragging effects to the
case of a rotating superconductor, we were able to express the absolute value
of the gravitomagnetic field involved to explain the Cooper pair mass anomaly
previously reported by Tate. Although our analysis predicts large
gravitomagnetic fields originated by superconductive gyroscopes, those should
not affect the measurement of the Earth gravitomagnetic field by the Gravity
Probe-B satellite. However, the hypothesis might be well suited to explain a
mechanical momentum exchange phenomena reported for superfluid helium. As a
possible explanation for those abnormally large gravitomagnetic fields in
quantum materials, the reduced speed of light (and gravity) that was found in
the case of Bose-Einstein condensates is analysed
Fiber-Optic-Gyroscope Measurements Close to Rotating Liquid Helium
We previously reported anomalous fiber-optic gyroscope signals observed above
rotating rings at temperatures close to liquid helium. Our results suggested
that the liquid helium itself may be the source of our observed phenomenon. We
constructed a new cryostat experiment that allows rotating a large quantity of
liquid helium together with a superconducting niobium tube. The facility is
built in such a way that our gyroscope can be placed directly in the center of
rotation along the axis; however, the cryostat is built around the gyroscope to
allow measuring without interference of helium liquid or gas. An anomalous
signal was found of similar value compared to our previous measurements with a
changed sign. As this measurement was done at a different location (center
position) with respect to our old setup (top position), first hints for a
possible field distribution of this phenomenon can be made. However, due to
lower angular velocities used in this new setup so far, our measurement
resolution was close to three times the resolution of our gyroscope and hence
our data represent work in progress.Comment: To appear in the SPESIF-2010 conference proceedings published by AI
- …