High-Tc superconducting detector for highly-sensitive microwave magnetometry

Abstract

We have fabricated arrays of High-T c Superconducting Quantum Interference Devices (SQUIDs) with randomly distributed loop sizes as sensitive detectors for Radio-Frequency (RF) waves. These subwavelength size devices known as Superconducting Quantum Interference Filters (SQIFs) detect the magnetic component of the electromagnetic field. We used a scalable ion irradiation technique to pattern the circuits and engineer the Josephson junctions needed to make SQUIDs. Here we report on a 300 SQUIDs series array with loops area ranging from 6 to 60 µm 2 , folded in a meander line covering a 3.5 mm×120 µm substrate area, made out of a 150 nm thick YBa 2 Cu 3 O 7 (YBCO) film. Operating at a temperature T = 66 K in an un-shielded magnetic environment, under low DC bias current (I = 60 µA) and DC magnetic field (B = 3 µT), this SQIF can detect a magnetic field of a few pT at a frequency of 1.125 GHz, which corresponds to a sensitivity of a few hundreds of fT/ √ Hz, and shows linear response over 7 decades in RF power.This work is a promising approach for the realization of low dissipative sub-wavelength GHz magnetometers.

A linear magnetic flux-to-voltage transfer function of a differential DC SQUID

“…The SQA formation can serve for the increase in dynamic range and transfer coefficient [12]. HTS-based SQUID arrays recently attracted attention due to the progress in fabrication of stepedge junctions [5] and the ones made with focused ion beam [8,36]. However, consideration of DSQUIDbased array requires complication of the model with taking into account the noise and inductive coupling between cells [6,37].…”

Superconducting proximity effect in $d$-wave cuprate/ graphene heterostructures

“…For many of the compounds the superconducting critical temperature T C exceeds the normal boiling point of nitrogen which, accompanied by large critical currents and fields, confers to the cuprates much potential for a variety technological applications [57]. These span from high-current coated conductors [58], which can be used for example for the generation of high magnetic fields [59], to high sensitivity sensors such as bolometers [60,61] and transition edge detectors [62] or quantum interference devices [8,63] such as quantum antennas [9] and magnetometric sensors [64]. Another key property most cuprates share is that they exhibit a d-wave pairing.…”

On‐Demand Local Modification of High‐Tc Superconductivity in Few Unit‐Cell Thick Bi2Sr2CaCu2O8+δ

“…Patterning of YBa 2 Cu 3 O 7+δ using helium ions, [ 13 ] and oxygen ions [ 14 ] in combination with conventional lithographic processes provide one possible strategy for realizing superconducting devices. For these device applications ion bombardment can lead to structural damages and the process entails multiple steps to protect the high‐ T c superconductor.…”