Atomic-scale magnetometry of distant nuclear spin clusters via nitrogen-vacancy spin in diamond

Abstract

The detection of single nuclear spins is an important goal in magnetic resonance spectroscopy. Optically detected magnetic resonance can detect single nuclear spins that are strongly coupled to an electron spin, but the detection of distant nuclear spins that are only weakly coupled to the electron spin has not been considered feasible. Here, using the nitrogen-vacancy centre in diamond as a model system, we numerically demonstrate that it is possible to detect two or more distant nuclear spins that are weakly coupled to a centre electron spin if these nuclear spins are strongly bonded to each other in a cluster. This cluster will stand out from other nuclear spins by virtue of characteristic oscillations imprinted onto the electron spin decoherence profile, which become pronounced under dynamical decoupling control. Under many-pulse dynamical decoupling, the centre electron spin coherence can be used to measure nuclear magnetic resonances of single molecules. This atomic-scale magnetometry should improve the performance of magnetic resonance spectroscopy for applications in chemical, biological, medical and materials research, and could also have applications in solid-state quantum computing.

Optically detected cross-relaxation spectroscopy of electron spins in diamond

“…The NV 0 centre is a 'dark state' of the NV À centre because it requires shorter excitation and detection wavelength than those optimized for NV À centre, and unlike the NV À centre it has not been detected previously using ODMR [27][28][29] . EPR spectra of the NV 0 centre have been observed only recently for its 4 A 2 exited state under laser illumination 25 . We demonstrate here that the 4 A 2 exited state of the NV 0 centre can also be detected by ODMR via its coupling to the NV À centre.…”

“…Recent experiments have employed single NV À centres to detect distant nuclear spins in diamond [4][5][6][7][8] and external, nanoscale nuclear spin ensembles 9,10 , laying the foundations for routine magnetic resonance imaging with nanometre resolution 11,12 . Electron spins, in the form of either paramagnetic centres in the diamond lattice or radicals intimately associated with the diamond surface, have also been optically detected through their coupling to the NV À centre [13][14][15] .…”

Maximizing the purity of a qubit evolving in an anisotropic environment

“…83,84 The methods presented here can be used to preserve pure qubit states in spite of these resonant dips [blue dashed curve in Fig. 12(c)], when it is not possible to suppress these dips with faster π-pulses [ Fig.…”

Sensitive imaging of electromagnetic fields with paramagnetic polar molecules

“…The ratio of the minimal detectable magnetic fields in experiments with cold atoms [18] and molecules is given by B at min /B mol min = 2cd 12 α /( √ 3µ B )(assuming the same interaction time τ , the same number of particles and the same detection efficiency in both cases), which for typical molecules with d ∼ 1 a.u. amounts to ∼100-fold higher sensitivity using the proposed scheme.…”