Spectrally stable nitrogen-vacancy centers in diamond formed by carbon implantation into thin microstructures

Abstract

The nitrogen-vacancy center (NV) in diamond, with its exceptional spin coherence and convenience in optical spin initialization and readout, is increasingly used both as a quantum sensor and as a building block for quantum networks. Employing photonic structures for maximizing the photon collection efficiency in these applications typically leads to broadened optical linewidths for the emitters, which are commonly created via nitrogen ion implantation. With studies showing that only native nitrogen atoms contribute to optically coherent NVs, a natural conclusion is to either avoid implantation completely or substitute nitrogen implantation by an alternative approach to vacancy creation. Here, we demonstrate that implantation of carbon ions yields a comparable density of NVs as implantation of nitrogen ions and that it results in NV populations with narrow optical linewidths and low charge-noise levels even in thin diamond microstructures. We measure a median NV linewidth of 150 MHz for structures thinner than 5 μm, with no trend of increasing linewidths down to the thinnest measured structure of 1.9 μm. We propose a modified NV creation procedure in which the implantation is carried out after instead of before the diamond fabrication processes and confirm our results in multiple samples implanted with different ion energies and fluences.

Spectral stability of V2-centres in sub-micron 4H-SiC membranes

“…All of our investigated emitters with stable PLE showed narrow linewidths below 200 MHz, which is comparable with PLE-linewidths from NV-centres in µm-thick membranes [38,39] and GeV-centres in sub-µm-thick membranes [40]. Moreover, all emitters in the ∼0.65 µmthick membrane showed linewidths below 100 MHz, which is comparable with recent studies on nanophotonicallyintegrated V − Si -centres in 4H-SiC [17,19], as well as diamond-SnV centres [41,42].…”

Shallow Silicon Vacancy Centers with Lifetime-Limited Optical Linewidths in Diamond Nanostructures

“…PLE experiments with solid state emitters often require regular application of optical charge-resetting pulses using off-resonant laser light. ,,, Such charge resetting pulses are usually applied at wavelengths between 510 to 532 nm to undo deionization events the emitter can undergo under resonant excitation. Importantly, such repumping perturbs the charge environment of the emitter and thus induces inhomogeneous broadening, ,, precluding the observation of lifetime-limited optical linewidths.…”