A low-temperature high-sensitivity torsion balance magnetometer with in situ stator adjustment

Abstract

The development of highly sensitive magnetometers using a capacitative proximity detection of the rotor position, for the use at temperatures below 10 mK, was described. The magnetometer responsivity is inversely proportional to the square of the rotor-stator separation and the novel linear motor technique. It is accompanied by effective vibration isolation and optimized capacitance bridge electronics, achieving a resolution 6.5 × 10-12 N m Hz-1/2. This resolution allows for experiments that probe the family of quantum fluid states responsible for the fractional quantum Hall effect, even at filling factors greater than one. Show more