Imaging oersted field around current flowing wire based on a diamond scanning magnetometer

Abstract

We demonstrate imaging current flow in a transport device by measuring the current-induced Oersted field. A diamond scanning magnetometer that hosts a single nitrogen-vacancy (NV) center at the tip apex is used to obtain the image. We fabricate a U-shape of Pt wire and study evolution of the Oersted field as the current continuously changes its direction along the wire. We find a good agreement between the obtained results and the simulated images based on the Biot-Savart law. In order to show the capability of imaging different field components, we perform the same experiment but with two different axes of the NV center. This work provides a novel imaging method of the current profile and can be applied to various transport experiments.