Frequency-Tunable Current Imaging using a Quantum-Mixer Microscope Based on Nitrogen-Vacancy Centers in Diamond

Abstract Wide-field magnetic imagers using nitrogen-vacancy (NV) centers in diamond yield high-resolution images for various applications, including magnetic field imaging (MFI) of electronics. Despite the ongoing successes of this emerging technique for passively interrogating electronics components (including failure analysis troubleshooting), most of the focus has been on sensing DC and low-frequency currents, due to the technical challenges associated with measuring higher-frequency magnetic fields. Here, we overcome these existing challenges and adapt a recently developed technique for sensing MHz-frequency AC fields, a “quantum frequency mixing” approach. We demonstrate the instrument’s capabilities by imaging the current through a fabricated spiral test structure at various frequencies with a ~1 mm2 field of view. Finally, we discuss anticipated future applications in electronics interrogation and failure analysis for this imaging technique.