Determination of intrinsic effective fields and microwave polarizations by high-resolution spectroscopy of single nitrogen-vacancy center spins

Abstract

We present high-resolution optically detected magnetic resonance spectroscopy on single nitrogenvacancy (NV) center spins in diamond at and around zero magnetic field. The experimentally observed transitions depend sensitively on the interplay between the microwave (MW) probing field and the local intrinsic effective field comprising strain and electric fields, which act on the NV spin.Based on a theoretical model of the magnetic dipole transitions and the MW driving field, we extract both the strength and the direction of the transverse component of the effective field. Our results reveal that for the diamond crystal under study, strain is the dominant contribution to the effective field. Our experiments further yield a method for MW polarization analysis in a tunable, linear basis, which we demonstrate on a single NV spin. Our results are of importance to low-field quantum sensing applications using NV spins and form a relevant addition to the ever-growing toolset of spinbased quantum sensing.

Optically Enhanced Electric Field Sensing Using Nitrogen-Vacancy Ensembles

“…In this Letter, we present two main results aimed at overcoming these obstacles. First, by leveraging an interplay between spin-selective optical pumping and internal electric fields [53,63], we propose a method to extract the NV's excited-state susceptibilities directly from ensemble optically detected magnetic resonance (ODMR) measurements. We implement this approach in a high-NV-density sample (ρ NV ∼ 8 ppm), extracting the transverse and longitudinal susceptibilities as χ e ⊥ = 1.4 ± 0.1 MHz/(V/cm) and χ e = 0.7 ± 0.1 MHz/(V/cm), respectively.…”

Defect Nanostructure and its Impact on Magnetism of α‐Cr2O3 Thin Films

“…[9,26] To address the magnetic microstructure of the magnetron-sputtered Cr 2 O 3 samples, we performed nitrogenvacancy (NV) microscopy. [34] In this study, a diamond tip with a single spin defect is scanned over the surface of the sample and allowing us to image the local magnetic stray field pattern. [9,26,35] A marked difference in the antiferromagnetic domain pattern was observed between single crystals (Figure S4a, Supporting Information) and thin-film samples (Figure S4b, Supporting Information).…”

Magnetic sensing at zero field with a single nitrogen-vacancy center

“…As mentioned above, one could also use a static local bias field instead of a flipping bias ( 14 N, 15 N) which would in turn avoid the need of specifically designed MW structures to produce circularly polarized MWs. A promising candidate for this is an axial 13 C nucleus, which can, depending on the exact location, have flipping rates well below 10 −4 Hz or in an ideal case even zero.…”

“…A simplified energy-level diagram of NV-ground state is shown in figure 1(a). The NV-center energy levels close to zero ambient field are described by the following Hamiltonian [15][16][17]. where h is Planck's constant, γ NV = 28 GHz T −1 the electron gyromagnetic ratio, B the magnetic field vector, S the electronic spin vector with its components S x , S y , S z , respectively, and D 0 ≈ 2.87 GHz the axial zero field splitting.…”