The Laser Switch in SQUID Measurements: Fundamental Experiments and Low Frequency Noise Reduction
We are developing a laser-driven superconducting switch. The switch has been used in several fundamental physics experiments which utilize SQUIDs, and in a noise reduction scheme for low-frequency SQUID measurements. The experiments include characterization studies of the laser switch itself, a direct measurement of the pinning force on a single vortex, the measurement of the Cooper pair mass, a study of the Aharonov-Bohm effect, and a measurement of the kinetic inductance of a superconducting thin-film. The noise reduction scheme is based on modulating the input circuit of a SQUID at a frequency above its 1/f knee. The demodulated output is then devoid of the SQUID noise below the modulation frequency. This paper reviews these experiments and reports on their status.
KeywordsVortex Quartz Epoxy Coherence Tate
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