2018/03/20 by Farshad Foroughi, F. Foroughi, Jan-Michael Mol +9
Engineering · Physics and Astronomy · #Advanced Electrical Measurement Techniques #Josephson effect #Magnetic flux #Magnetometer #Microscopy #Noise (video) #Physics of Superconductivity and Magnetism #Resonance (particle physics) #Scanning SQUID microscopy #Scanning probe microscopy #Squid #Superconducting and THz Device Technology #Superconductivity #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1063/1.5030489
published as Appl. Phys. Lett. 112, 252601 (2018)
arxiv created 2018/03/20 · openalex created_date 2018/03/29 · openalex publication_date 2018/06/18 · arxiv updated 2018/06/25 · openalex updated_date 2026/08/06
We have designed and characterized a micro-SQUID with dispersive readout for use in low temperature scanning probe microscopy systems. The design features a capacitively shunted RF SQUID with a tunable resonance frequency from 5 to 12 GHz, micrometer spatial resolution, and integrated superconducting coils for local application of magnetic fields. The SQUID is operated as a nonlinear oscillator with a flux- and power-dependent resonance frequency. Measurements for device characterization and noise benchmarking were carried out at 4 K. The measured flux noise above 10 kHz at 4 K is 80 nΦ0 Hz−1∕2 at a bandwidth of 200 MHz. Estimations suggest that one can benefit from parametric gain based on inherent nonlinearity of the Josephson junction and reduce the flux noise to 30 nΦ0Hz–1∕2 at 100 mK, which corresponds to 10.6 μBHz–1∕2 for a magnetic moment located at the center of the pickup loop.