Title :
High-T/sub c/ multilayer magnetometers with improved 1/f noise
Author :
Ludwig, F. ; Dantsker, E. ; Koelle, D. ; Kleiner, R. ; Miklich, A.H. ; Nemeth, D.T. ; Clarke, J. ; Drung, D. ; Knappe, S. ; Koch, H.
Author_Institution :
Dept. of Phys., California Univ., Berkeley, CA, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
We have fabricated three types of high T/sub c/ magnetometers using a YBa/sub 2/Cu/sub 3/O/sub 7-x/-SrTiO/sub 3/-YBa/sub 2/Cu/sub 3/O/sub 7-x/, multilayer process: multiturn flux transformers coupled to single layer dc SQUIDs in a flip-chip arrangement, multiturn flux transformers integrated with dc SQUIDs, and multiloop magnetometers (fractional turn SQUIDs). The magnetic field noise of the best flip-chip magnetometer was 74 fTHz/sup -1/2/ at 1 Hz and 31 fTHz/sup -1/2/ at 1 kHz. The magnetic field noise of the multiloop magnetometer, measured in a YBCO tube, was 37 fTHz/sup -1/2/ at 1 Hz and 18 fTHz/sup -1/2/ at 1 kHz.<>
Keywords :
1/f noise; SQUID magnetometers; barium compounds; electron device manufacture; flip-chip devices; high-temperature superconductors; magnetic noise; strontium compounds; superconducting device testing; superconducting thin films; yttrium compounds; 1 Hz; 1 kHz; 1/f noise; YBa/sub 2/Cu/sub 3/O/sub 7/-SrTiO/sub 3/-YBa/sub 2/Cu/sub 3/O/sub 7/; flip-chip arrangement; fractional turn SQUIDs; high T/sub c/ magnetometers; magnetic field noise; multilayer magnetometers; multiloop magnetometers; multiturn flux transformers; single layer dc SQUIDs; 1f noise; Couplings; Magnetic field measurement; Magnetic multilayers; Magnetic noise; Milling; SQUID magnetometers; Superconducting device noise; Transformers; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
