Noise measurements in a 2-hole radio frequency SQUID at liquid nitrogen temperature

The authors report measurements of the noise in a two-hole RF SQUID (superconducting quantum interference device) fabricated from bulk YBCO by an erosion technique in the frequency range 30 mHz to 1 kHz. Above 100 Hz the noise is essentially white with an RMS (root mean square) value of 5*10/sup -4/ phi /sub 0// square root Hz and is dominated by noise from the electronics. Below 10-Hz the noise power rises as 1/f/sup 0/9/.<
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