SQUID (Sperconducting QUantum Interference Device) is the most sensitive magnetometer to-date that uses quantum phenomena to detect magnetic flux. The SQUID is made of a superconducting ring and 2 parallel Josepheson junctions. Using the effects of flux quantization and josephson tunneling the SQUID converts magnetic flux into measurable voltage.

Using vibrations to improve SQUID sensitivity

Vibrations are usually undesired in imaging systems, because they may reduce system performance. We developed a method to utilize mechanical vibrations to increase the sensitivity of our sensor. Imposed vibrations make the samples’ position periodically time dependent, allowing the measurement of the AC magnetic field generated at specific excitation frequencies, instead of the noisy DC signal. We developed a model for the spectral and spatial response of the vibrating signal, and demonstrated the increased sensitivity with our scanning SQUID.​

Our technique can be readily applied to various other imaging systems where high sensitivity is desired.​Appl. Phys. Lett. 113, 173101 (2018)