Fig. 1: NV magnetometry of the interlayer antiferromagnet CrSBr.
From: Nitrogen-vacancy magnetometry of CrSBr by diamond membrane transfer
a Schematics of the sample. A diamond membrane with a shallowly implanted layer of NV centers (at the depth of about 70 nm, shown with the layer in red) is placed onto the CrSBr crystal. The NV centers consist of a substitutional nitrogen atom adjacent to a vacancy in the diamond lattice. They are oriented along the [111] directions in the diamond crystal, at α = 54.7° with respect to the sample normal. We use the subset of NVs oriented along \({\hat{S}}_{{{{\rm{NV}}}}}=\sin \!\alpha \,\hat{x}+\cos \!\alpha \,\hat{z}\) for magnetometry. A small external magnetic field Bex = 5.6 mT along \({\hat{S}}_{{{{\rm{NV}}}}}\) enables selective driving of the ms = 0 ↔ − 1 electron spin resonance (ESR) transition of the target NV subset using microwaves applied via the stripline. A green laser (520 nm) excites the spin-dependent NV photoluminescence (PL). b Illustration of the modulation of the NV ESR frequency by the stray fields (purple arrows) generated by the uncompensated CrSBr magnetization at the CrSBr edges. The CrSBr magnetic stacking order is indicated by black arrows. The plot shows the expected spatial dependence of the CrSBr stray fields and the corresponding change of the NV ESR frequency (fESR = f0 − γdBNV) sensed by the selected NV family, where f0 = D − γBex with D = 2.87 GHz the NV zero-field splitting.
