Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical review. B./Physical review. B

Density functional theory study on magnetically detecting positively charged nitrogen-vacancy center in diamond

Claire J. Meara, M. J. Rayson, P. R. Briddon, Jonathan P. Goss

Published Sep 10, 2019• 10 citations
Publisher

Abstract

A quantum-chemical study of the positive charge-state of the nitrogen-vacancy center in diamond is presented. Charge control of this promising qubit candidate is a focus of diamond quantum technology research, as currently charge stability relating to surfaces and nearby defects causes some difficulties for quantum applications. To demonstrate full charge control over the nitrogen vacancy, all three charge states should be identified and the processes that lead to charge state changes understood. However, experimental markers for the positive state remain elusive compared to the readily detectable zero-phonon lines of the neutral and negative. In this work we present predicted hyperfine and zero-field splitting tensors as clear signatures of the normally spinless ${\mathrm{NV}}^{+}\phantom{\rule{4pt}{0ex}}(^{1}\mathrm{A}_{1}$ ground state) by probing a long-lived spin-triplet excited-state $\ensuremath{\sim}0.7$ eV above the ${\mathrm{NV}}^{+}$ ground state. We find a relatively narrow excitation energy range of approximately 0.7--1.1 eV between excitation into an $^{3}\mathrm{E}$ state and conversion into the neutral charge state. To provide insight into the thermal stability of the positive charge state, we have calculated binding and diffusion energies for both charged and uncharged systems. We predict, given that the activation energies are only weakly charge state dependent, all three charge states would diffuse in the 1600--$1900{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\text{C}$ range, but the positive state has a significantly lower binding energy, suggesting that it will dissociate at temperatures around $1000{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}$ rather than migrate.

DOI
10.1103/physrevb.100.104108

Related papers

Theory of the neutral nitrogen-vacancy center in diamond and its application to the realization of a qubit

Ádám Gali

The negatively charged nitrogen-vacancy defect $({\text{NV}}^{\ensuremath{-}})$ in diamond has attracted much attention in recent years in qubit and biological applications. The negative charge is donated from nearby nitrogen donors that could limit or stem the successful application of ${\text{NV}}^{\ensuremath{-}}$. In this study, we identify the neutral nitrogen-vacancy defect $({\text{NV}}^{0})$ by ab initio supercell calculations through the comparison of the measured and calculated hyperfine tensors of the ${^{4}A}_{2}$ excited state. Our analysis shows that (i) the spin state can be selectively occupied optically, (ii) the electron spin state can be manipulated by time-varying magnetic field, and (iii) the spin state may be read out optically. Based on this ${\text{NV}}^{0}$ is a hope for realizing qubit in diamond without the need of nitrogen donors. In addition, we propose that ${\text{NV}}^{0}$ may be more sensitive magnetometer than the ultrasensitive ${\text{NV}}^{\ensuremath{-}}$.

Physical Review B•Jun 30, 2009•114 citations

Theory of neutral nitrogen-vacancy center in diamond and its qubit application

Ádám Gali

The negatively charged nitrogen-vacancy defect (NV)$^-$ in diamond has attracted much attention in recent years in qubit and biological applications. The negative charge is donated from nearby nitrogen donors that could limit or stem the successful application of (NV)$^-$. In this Letter, we unambiguously identify the \emph{neutral} nitrogen-vacancy defect (NV$^0$) by \emph{ab initio} supercell calculations. Our analysis shows that i) the spin state can be \emph{selectively} occupied optically, ii) the electron spin state can be manipulated by time-varying magnetic field, and iii) the spin state may be read out optically. Based on this NV$^0$ is a new hope for realizing qubit in diamond \emph{without} the need of nitrogen donors.

arXiv:0902.2387•Feb 13, 2009•0 citations

Charge State Equilibration of Nitrogen-Vacancy Center Ensembles in Diamond: The Role of Electron Tunneling

Anonymous, Chris G. Van de Walle, Lukas Razinkovas +1 more

The charge state stability of nitrogen-vacancy (NV) centers critically affects their application as quantum sensors and qubits. Understanding charge state conversion and equilibration is important not only for NV centers in diamond but also for defects and impurities in wide-bandgap materials in general. The mechanisms by which these centers change charge state upon optical or electronic excitation without the presence of mobile carriers remain unclear. Here, we elucidate this issue for the case of photoionization of NV center ensembles. Using pump-probe spectroscopy, we ionize negatively charged NV centers and monitor the recovery of NV^{-} on timescales of up to several seconds. We find that the recovery rate depends strongly on the concentration of surrounding nitrogen donors. Remarkably, the equilibration dynamics exhibit no discernible dependence on temperature, ruling out thermally activated processes. We develop a multiphonon-assisted electron-tunneling model, supported by density-functional calculations, that explains the measurements and identifies tunneling as the equilibration mechanism. Because tunneling rates depend exponentially on donor separation, the random distribution of nitrogen donors spreads recovery times from nanoseconds to hours or longer.

arXiv:2512.00952•Physical Review Letters•Sep 8, 2026•1 citation

New insight into the spin-conserving excitation of the negatively charged nitrogen-vacancy center in diamond

Bei Deng, R. Q. Zhang, Xingqiang Shi

The negatively charged nitrogen-vacancy (N-V(-)) color center in diamond is an important solid-state single photon source for applications to quantum communication and distributed quantum computation. Its full usefulness relies on sufficient radiative emission of the optical photons which requires realizable control to enhance emission into the zero-phonon line (ZPL) but until now is still a challenge. Detailed understanding of the associated excitation process would be of essential importance for such objective. Here we report a theoretical work that probes the spin-conserving optical excitation of the N-V(-) center. Using density-functional-theory (DFT) calculations, we find that the ZPL and the phonon-side band (PSB) depend sensitively on the axial strain of the system. Besides, we find a relatively small PSB appearing at about 100 GPa in the emission spectrum at low temperatures, which provides a means to enhance the coherent emission of the N-V(-) center in quantum optical networks.

Scientific Reports•Jun 3, 2014•16 citations

Photoexcitation and recombination processes of the neutral nitrogen-vacancy center in diamond from first principles

Gergő Thiering, Ádám Gali

Nitrogen-vacancy (NV) complex in diamond is one of the most prominent solid state defects as the negatively charged NV defect (NV−) is a leading contender for quantum technologies. In quantum information processing applications, NV− is photoexcited that often leads to photoionization to neutral NV defect, NV0, and re-ionization back to NV− should occur to control the S=1 spin of NV−. As a consequence, understanding the photophysics of NV0 is crucial for controlling NV−. Furthermore, recent studies have shown that the S=1/2 electron spin of NV0 can also be initialized and read out at certain conditions that turns single NV0 a potential quantum bit. Quantum optics protocols rest on detailed knowledge on the electronic structure of the given system, which is obviously missing for NV0 in diamond. In this study, we combine the group theory and density functional theory calculations toward exploring the nature of the ground and excited states of NV0. We show that the effective three-electron system of NV0 leads to high correlation effects that make this system very challenging for ab initio simulations.

Journal of Applied Physics•Aug 27, 2024•12 citations

A neutral oxygen-vacancy center in diamond: A plausible qubit candidate and its spintronic and electronic properties

Y. G. Zhang, Zheng Tang, Xuan Zhao +6 more

Spintronic and electronic properties of a neutral oxygen-vacancy (O-V) center, an isoelectronic defect similar to the negatively charged nitrogen-vacancy center in diamond, were studied by combining first-principles calculations and a mean-field theory for spin hyperfine interaction. It is elucidated that the neutral O-V center is stable in the p-type diamond and possesses an S = 1 triplet ground state and four spin-conserved excited states with the spin coherence times in an order of second at T = 0 K. The results indicate that the neutral O-V center is another promising candidate for spin coherent manipulation and qubit operation.

Applied Physics Letters•Aug 4, 2014•18 citations
A quantum-chemical study of the positive charge-state of the nitrogen-vacancy center in diamond is presented. Charge control of this promising qubit candidate is a focus of diamond quantum technology research, as currently charge stability relating to surfaces and nearby defects causes some difficulties for quantum applications. To demonstrate full charge control over the nitrogen vacancy, all three charge states should be identified and the processes that lead to charge state changes understood. However, experimental markers for the positive state remain elusive compared to the readily detectable zero-phonon lines of the neutral and negative. In this work we present predicted hyperfine and zero-field splitting tensors as clear signatures of the normally spinless NV+(1A1{\mathrm{NV}}^{+}\phantom{\rule{4pt}{0ex}}(^{1}\mathrm{A}_{1}NV+(1A1​ ground state) by probing a long-lived spin-triplet excited-state \ensuremath∼0.7\ensuremath{\sim}0.7\ensuremath∼0.7 eV above the NV+{\mathrm{NV}}^{+}NV+ ground state. We find a relatively narrow excitation energy range of approximately 0.7--1.1 eV between excitation into an 3E^{3}\mathrm{E}3E state and conversion into the neutral charge state. To provide insight into the thermal stability of the positive charge state, we have calculated binding and diffusion energies for both charged and uncharged systems. We predict, given that the activation energies are only weakly charge state dependent, all three charge states would diffuse in the 1600--1900\ensuremath∘C1900{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\text{C}1900\ensuremath∘C range, but the positive state has a significantly lower binding energy, suggesting that it will dissociate at temperatures around 1000\ensuremath∘C1000{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}1000\ensuremath∘C rather than migrate.
The negatively charged nitrogen-vacancy defect $({\text{NV}}^{\ensuremath{-}})$ in diamond has attracted much attention in recent years in qubit and biological applications. The negative charge is donated from nearby nitrogen donors that could limit or stem the successful application of ${\text{NV}}^{\ensuremath{-}}$. In this study, we identify the neutral nitrogen-vacancy defect (NV0)({\text{NV}}^{0})(NV0) by ab initio supercell calculations through the comparison of the measured and calculated hyperfine tensors of the 4A2{^{4}A}_{2}4A2​ excited state. Our analysis shows that (i) the spin state can be selectively occupied optically, (ii) the electron spin state can be manipulated by time-varying magnetic field, and (iii) the spin state may be read out optically. Based on this NV0{\text{NV}}^{0}NV0 is a hope for realizing qubit in diamond without the need of nitrogen donors. In addition, we propose that NV0{\text{NV}}^{0}NV0 may be more sensitive magnetometer than the ultrasensitive ${\text{NV}}^{\ensuremath{-}}$.
The negatively charged nitrogen-vacancy defect (NV)−^-− in diamond has attracted much attention in recent years in qubit and biological applications. The negative charge is donated from nearby nitrogen donors that could limit or stem the successful application of (NV)−^-−. In this Letter, we unambiguously identify the \emph{neutral} nitrogen-vacancy defect (NV0^00) by \emph{ab initio} supercell calculations. Our analysis shows that i) the spin state can be \emph{selectively} occupied optically, ii) the electron spin state can be manipulated by time-varying magnetic field, and iii) the spin state may be read out optically. Based on this NV0^00 is a new hope for realizing qubit in diamond \emph{without} the need of nitrogen donors.
The charge state stability of nitrogen-vacancy (NV) centers critically affects their application as quantum sensors and qubits. Understanding charge state conversion and equilibration is important not only for NV centers in diamond but also for defects and impurities in wide-bandgap materials in general. The mechanisms by which these centers change charge state upon optical or electronic excitation without the presence of mobile carriers remain unclear. Here, we elucidate this issue for the case of photoionization of NV center ensembles. Using pump-probe spectroscopy, we ionize negatively charged NV centers and monitor the recovery of NV^{-} on timescales of up to several seconds. We find that the recovery rate depends strongly on the concentration of surrounding nitrogen donors. Remarkably, the equilibration dynamics exhibit no discernible dependence on temperature, ruling out thermally activated processes. We develop a multiphonon-assisted electron-tunneling model, supported by density-functional calculations, that explains the measurements and identifies tunneling as the equilibration mechanism. Because tunneling rates depend exponentially on donor separation, the random distribution of nitrogen donors spreads recovery times from nanoseconds to hours or longer.
The negatively charged nitrogen-vacancy (N-V(-)) color center in diamond is an important solid-state single photon source for applications to quantum communication and distributed quantum computation. Its full usefulness relies on sufficient radiative emission of the optical photons which requires realizable control to enhance emission into the zero-phonon line (ZPL) but until now is still a challenge. Detailed understanding of the associated excitation process would be of essential importance for such objective. Here we report a theoretical work that probes the spin-conserving optical excitation of the N-V(-) center. Using density-functional-theory (DFT) calculations, we find that the ZPL and the phonon-side band (PSB) depend sensitively on the axial strain of the system. Besides, we find a relatively small PSB appearing at about 100 GPa in the emission spectrum at low temperatures, which provides a means to enhance the coherent emission of the N-V(-) center in quantum optical networks.
Nitrogen-vacancy (NV) complex in diamond is one of the most prominent solid state defects as the negatively charged NV defect (NV−) is a leading contender for quantum technologies. In quantum information processing applications, NV− is photoexcited that often leads to photoionization to neutral NV defect, NV0, and re-ionization back to NV− should occur to control the S=1 spin of NV−. As a consequence, understanding the photophysics of NV0 is crucial for controlling NV−. Furthermore, recent studies have shown that the S=1/2 electron spin of NV0 can also be initialized and read out at certain conditions that turns single NV0 a potential quantum bit. Quantum optics protocols rest on detailed knowledge on the electronic structure of the given system, which is obviously missing for NV0 in diamond. In this study, we combine the group theory and density functional theory calculations toward exploring the nature of the ground and excited states of NV0. We show that the effective three-electron system of NV0 leads to high correlation effects that make this system very challenging for ab initio simulations.
Spintronic and electronic properties of a neutral oxygen-vacancy (O-V) center, an isoelectronic defect similar to the negatively charged nitrogen-vacancy center in diamond, were studied by combining first-principles calculations and a mean-field theory for spin hyperfine interaction. It is elucidated that the neutral O-V center is stable in the p-type diamond and possesses an S = 1 triplet ground state and four spin-conserved excited states with the spin coherence times in an order of second at T = 0 K. The results indicate that the neutral O-V center is another promising candidate for spin coherent manipulation and qubit operation.