Fig. 1: Scanning NV electrometer.
From: Imaging ferroelectric domains with a single-spin scanning quantum sensor
a, The NV centre is located at the apex of the diamond tip and is oscillated in shear mode through the electrical drive of a tuning fork (not shown) while it is scanned over the surface. Laser and microwave pulses synchronized to the drive are used for signal readout. A three-axis piezo stage underneath the sample is used for positioning. b, Geometry of tip and sample with the vector orientations of the NV spin, magnetic bias field and sample electric field. Sample surface charges and screening charges on the tip are also shown. c, The in-plane electric field detection axis (purple) is determined by the in-plane direction of the magnetic bias field (grey). (x, y, z) and (xNV, yNV, zNV) denote the laboratory and NV frames of reference (see Methods for definition). d, Spin-echo pulse scheme synchronized to the tip oscillation for the a.c. measurement of the electric field gradient.
