Subdiffraction optical manipulation of the charge state of nitrogen vacancy center in diamond

Abstract

As a potential candidate for quantum computation and metrology, the nitrogen vacancy (NV) center in diamond presents both challenges and opportunities resulting from charge-state conversion. By utilizing different lasers for the photon-induced charge-state conversion, we achieved subdiffraction charge-state manipulation. The charge-state depletion (CSD) microscopy resolution was improved to 4.1 nm by optimizing the laser pulse sequences. Subsequently, the electron spin-state dynamics of adjacent NV centers were selectively detected via the CSD. The experimental results demonstrated that the CSD can improve the spatial resolution of the measurement of NV centers for nanoscale sensing and quantum information. Keywords: charge state; NV center; photon ionization; super-resolution microscopy INTRODUCTION Because of the stable fluorescence and long coherence time of its spin state, the negatively charged nitrogen vacancy (NV 2 ) center in diamond has been studied extensively over the past decade. This defect has the potential to be used for quantum computation, 1-4 nanoscale metrology 5-8 and biological imaging. [9][10][11] To further extend the study of the interaction between a multi-NV center and the nanoscale sensing with the NV center, it is necessary to detect and control the NV center spin-state dynamics with high spatial resolution. 7,12-14 Therefore, many optical super-resolution microscopy techniques have been developed to detect single NV centers. [13][14][15][16][17] Among these methods, stimulated emission depletion (STED) microscopy 12,18-20 is one of the most promising. This method utilizes a doughnut-shaped laser to produce the position-dependent stimulated emission, which changes the fluorescence signal. With STED, the electron spin resonance signals of NV centers have been detected with a resolution lower than the diffraction limit. 12,21,22 A new super-resolution microscopy technique was recently developed by Han et al. 15 The authors replaced the stimulated excitation of STED with the dark-state pumping of NV centers. The dark state was later proven to be the neutral charge NV center (NV 0 ) by other groups. [23][24][25] The charge-state conversion results in a change of the local field in diamond 26 and the spectral diffusion of the NV center. 24,27 For high-fidelity quantum manipulation, the charge state should be well controlled. 28 Based on the mechanism of charge-state conversion and super-resolution microscopy, 25,29,30 we demonstrated the optical manipulation of the charge state of an NV center with subdiffraction resolution. By changing the duration and power of laser

Mirror-enhanced super-resolution microscopy

“…In addition, MEANS-STED is broadly applicable to PSF engineering-based super-resolution techniques, including the pulsed or time-gated STED 20 , RESOLFT 4 , ground-state depletion, excitation-state absorption, saturation 38 , optical data storage 39 , upconversion 40 and charge-state depletion 41 . Compared with the other imaging techniques based on the recollection of the signal through interference to confine the axial resolution, including 4Pi 15 , I 5 M 14 and wide-field standing-wave microscopy 7 or mirrors combined with spatial light modulator 10,42 , MEANS is much simpler and does not require precise alignment of the mirror.…”

Designing spin-channel geometries for entanglement distribution

“…2 we show the dynamics of E while increasing the number of spins in the channel with a fixed NV separation of 40 nm [48,49]. We limit ourselves to a maximum of N = 12, since this is approaching the limit of our numerical capability.…”

Optical far-field super-resolution microscopy using nitrogen vacancy center ensemble in bulk diamond

“…The initialization-depletiondetection procedure repeated hundreds of times to obtain sufficient photons for each scanning pixel. The resolution of CSD nanoscopy is determined by the depletion rate, which can be improved, in principle, by increasing the power of the doughnut-shaped beam 25,26 .…”

“…However, the spatial resolution with conventional optical microscopy is limited by the diffraction. Recently, several different types of optical nanoscopy methods for NV center imaging have been developed [21][22][23][24][25][26][27] . Therefore, it is possible to use NV center ensemble arrays as probes to realize sub-diffraction spatial resolution quantum sensing.…”

“…Here, CSD nanoscopy of the NV center is utilized for this purpose 25,26 . The experimental setup is shown in Fig.…”