Work

Bandwidth-enhanced noise-suppressed current source enabled by a spin-exchange relaxation-free magnetometer

Year: 2026

Type: article

Abstract: This work investigates the behavior of a spin-exchange relaxation-free magnetometer integrated into the feedback branch of a closed-loop control circuit, designed to realize a noise-suppressed current source. In this configuration, the magnetometer bandwidth is enhanced by almost 2 orders of magnitude as compared to the open-loop setup. Incorporating an injection transformer, the proposed system effectively reduces current noise to below 3 n A / Hz over a broad frequency bandwidth, independent of dc-current offsets. Analysis of the system sensitivity reveals the performance to be currently limited by technical noise. If this were to be eliminated, the system would achieve a current-sensing sensitivity on the order of a few p A / Hz while maintaining perfect galvanic isolation from the target circuit.

Source: Physical Review Applied

DOI: 10.1103/3655-6w65