Control and readout hardware platform for quantum diamond magnetic gradiometer

A control and readout hardware platform, which is developed for the implementation of the quantum magnetic gradiometer based on the nitrogen-vacancy centers in diamond, is reported in this paper. The hardware platform is designed with a mother-daughter board architecture to facilitate multi-channel expansion. The mother board is used to realize the central control and data distribution for the platform, whereas a single daughter board can achieve the signal readout and the feedback control for one nitrogen-vacancy center vector magnetic probe, with an equivalent current noise below 16 pA/Hz1/2. The mother board is designed with a 10 × 20 cm2 printed-circuit-board, and the daughter board has a 5.7 × 23.3 cm2 dimension. The hardware platform has been implemented on the quantum diamond magnetic gradiometer, and the mother-daughter board architecture has an advantage in channel-scalable capacity. This study has a bright future to be applied in the quantum engineering applications that require expandable multi-channel signal readout.