Marcus W. Doherty

Electric-field sensing using single diamond spins.

The ability to sensitively detect charges under amb ient conditions would be a fascinating new tool benefitting a wide range of researchers ac ross disciplines. However, most current techniques are limited to low-temperature methods l ike single-electron transistors (SET)[1,2], single–electron electrostatic force microscopy[3] a nd scanning tunnelling microscopy [4]. Here we open up a new quantum metrology technique demons trating precision electric field measurement using a single nitrogen-vacancy defect entre(NV) spin in diamond. An AC electric field sensitivity reaching ~ 140V/cm/ √Hz has been achieved. This corresponds to the electric field produced by a single elementary char ge located at a distance of ~ 150 nm from our spin sensor with averaging for one second. By caref ul analysis of the electronic structure of the defect centre, we show how an applied magnetic fiel d influences the electric field sensing properties. By this we demonstrate that diamond defct centre spins can be switched between electric and magnetic field sensing modes and ident ify suitable parameter ranges for both detector schemes. By combining magnetic and electri c field sensitivity, nanoscale detection and ambient operation our study opens up new frontiers in imaging and sensing applications ranging from material science to bioimaging.

The negatively charged nitrogen-vacancy centre in diamond: the electronic solution

The negatively charged nitrogen-vacancy centre is a unique defect in diamond that possesses properties highly suited to many applications, including quantum information processing, quantum metrology and biolabelling. Although the unique properties of the centre have been extensively documented and utilized, a detailed understanding of the physics of the centre has not yet been achieved. Indeed, there persist a number of points of contention regarding the electronic structure of the centre, such as the ordering of the dark intermediate singlet states. Without a detailed model of the centres electronic structure, the understanding of the systems unique dynamical properties cannot effectively progress. In this work, the molecular model of the defect centre is fully developed to provide a self-consistent model of the complete electronic structure of the centre. The application of the model to describe the effects of electric, magnetic and strain interactions, as well as the variation of the centres fine structure with temperature, provides an invaluable tool to those studying the centre and a means of designing future empirical and ab initio studies of this important defect.

Electronic structure of the negatively charged silicon-vacancy center in diamond

The negatively-charged silicon-vacancy (SiV

Perfect alignment and preferential orientation of nitrogen-vacancy centers during chemical vapor deposition diamond growth on (111) surfaces

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Nanoscale detection of a single fundamental charge in ambient conditions using the NV - Center in diamond

) center in diamond is a promising single photon source for quantum communications and information processing. However, the centers implementation in such quantum technologies is hindered by contention surrounding its fundamental properties. Here we present optical polarization measurements of single centers in bulk diamond that resolve this state of contention and establish that the center has a

Electron–phonon processes of the silicon-vacancy centre in diamond

\langle111\rangle

Theory of the ground-state spin of the NV- center in diamond

aligned split-vacancy structure with

All-Optical Thermometry and Thermal Properties of the Optically Detected Spin Resonances of the NV– Center in Nanodiamond

D_{3d}

Temperature shifts of the resonances of the NV-center in diamond

symmetry. Furthermore, we identify an additional electronic level and evidence for the presence of dynamic Jahn-Teller effects in the centers 738 nm optical resonance.

Phonon-induced population dynamics and intersystem crossing in nitrogen-vacancy centers.

Synthetic diamond production is a key to the development of quantum metrology and quantum information applications of diamond. The major quantum sensor and qubit candidate in diamond is the nitrogen-vacancy (NV) color center. This lattice defect comes in four different crystallographic orientations leading to an intrinsic inhomogeneity among NV centers, which is undesirable in some applications. Here, we report a microwave plasma-assisted chemical vapor deposition diamond growth technique on (111)-oriented substrates, which yields perfect alignment (94% ± 2%) of as-grown NV centers along a single crystallographic direction. In addition, clear evidence is found that the majority (74% ± 4%) of the aligned NV centers were formed by the nitrogen being first included in the (111) growth surface and then followed by the formation of a neighboring vacancy on top. The achieved homogeneity of the grown NV centers will tremendously benefit quantum information and metrology applications.