A terraced scanning superconducting quantum interference device susceptometer with submicron pickup loops

Journal Article · Mon Dec 15 00:00:00 EST 2008 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3046098· OSTI ID:21175813

Koshnick, Nicholas C; Bert, Julie A; Hicks, Clifford W ^[1]; Huber, Martin E; Moler, Kathryn A ^[2]; Large, Jeff; Edwards, Hal ^[3]

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1. Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305 (United States)
2. Departments of Physics and Electrical Engineering, University of Colorado Denver, Denver, Colorado 80217 (United States)
3. Circuit Design Repair Laboratory, Texas Instruments, Dallas, Texas 75243 (United States)

Superconducting quantum interference devices (SQUIDs) can have excellent spin sensitivity depending on their magnetic flux noise, pickup loop diameter, and distance from the sample. We report a family of scanning SQUID susceptometers with terraced tips that position the pickup loops 300 nm from the sample. The 600 nm-2 {mu}m pickup loops, defined by focused ion beam, are integrated into a 12-layer optical lithography process allowing flux-locked feedback, in situ background subtraction and optimized flux noise. These features enable a sensitivity of {approx}70 electron spins per root hertz at 4 K.

• OSTI ID: 21175813
• Journal Information: Applied Physics Letters, Vol. 93, Issue 24; Other Information: DOI: 10.1063/1.3046098; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ELECTRONS
FEEDBACK
ION BEAMS
LAYERS
MAGNETIC FLUX
MAGNETIC SUSCEPTIBILITY
MAGNETOMETERS
NANOSTRUCTURES
NOISE
SENSITIVITY
SPIN
SQUID DEVICES