Fig. 3: Effects of the Berry phase generated by a rotating nanodiamond.
From: Quantum control and Berry phase of electron spins in rotating levitated diamonds in high vacuum
a Schematic of an NV center in the nanodiamond rotating around the z-axis in the absence of an external magnetic field. The small angle between BMW and the z-axis is due to the asymmetric design of the waveguide. b ODMRs of the levitated nanodiamond at rotation frequencies of 0.1 MHz (blue circles) and 14 MHz (red squares). c Experimentally measured FWHM of the ODMR spectrum as a function of rotation frequency (blue circles). Error bars show the standard deviations among three measurements. The red solid curve and orange dashed curve are theoretically calculated FWHMs at θ = 0° and θ = 20°, respectively. d Schematic of an NV center in the nanodiamond rotating around the z-axis in an external magnetic field. The magnetic field is along the z-axis and is about 100 G. e The upper panel (red squares) shows the ODMR of the levitated nanodiamond at a rotation frequency of 0.1 MHz and a pressure of 1.0 × 10−4 Torr. The bottom panel (gray circles) shows the ODMR of a nanodiamond without a stable rotation at the pressure of 10 Torr. The corresponding solid curves are the fittings with eight Lorentzian dips. f Experimentally measured frequency of the right-most dip of the ODMR spectrum of an NV center as a function of rotation frequency (blue circles). The green solid curve and violet dashed curve are theoretical calculations at θ = 20. 7° and θ = 24. 0°, respectively. The magenta dashed curve is a linear fitting of the resonance frequency. The error bars represent standard deviations among three measurements.
