Osipov Vladimir Yu, Treussart François, Zargaleh Soroush Abbasi, Takai Kazuyuki, Shakhov Fedor M, Hogan Benjamin T, Baldycheva Anna
Ioffe Institute, Polytechnicheskaya 26, St. Petersburg, 194021, Russia.
Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, 91405, Orsay, France.
Nanoscale Res Lett. 2019 Aug 16;14(1):279. doi: 10.1186/s11671-019-3111-y.
The content of nitrogen-vacancy (NV) colour centres in the nanodiamonds (DNDs) produced during the detonation of nitrogen-containing explosives was found to be 1.1 ± 0.3 ppm. This value is impressive for nanodiamonds of size < 10 nm with intentionally created NV centres. The concentration was estimated from the electron paramagnetic resonance as determined from the integrated intensity of the g = 4.27 line. This line is related with "forbidden" ∆m = 2 transitions between the Zeeman levels of a NV centre's ground triplet state. Confocal fluorescence microscopy enables detection of the red photoluminescence (PL) of the NV colour centres in nanoscale DND aggregates formed from the 5-nm nanoparticles. Subwavelength emitters consisting of NV with sizes a few times smaller than the diffraction-limited spot are clearly distinguished. We have further observed an abrupt drop in the PL intensity when mixing and anti-crossing of the ground and excited states spin levels in NV occurs under an applied external magnetic field. This effect is a unique quantum feature of NV centres, which cannot be observed for other visible domain light-emitting colour centres in a diamond lattice.
含氮炸药爆炸过程中产生的纳米金刚石（DND）中氮空位（NV）色心的含量为1.1±0.3 ppm。对于尺寸小于10 nm且有意制造NV中心的纳米金刚石而言，该值令人印象深刻。该浓度是通过电子顺磁共振，根据g = 4.27谱线的积分强度测定的。这条谱线与NV中心基态三重态的塞曼能级之间的“禁戒”Δm = 2跃迁有关。共聚焦荧光显微镜能够检测由5 nm纳米颗粒形成的纳米级DND聚集体中NV色心的红色光致发光（PL）。由尺寸比衍射极限光斑小几倍的NV组成的亚波长发射器清晰可辨。我们还观察到，在施加外部磁场时，当NV的基态和激发态自旋能级发生混合和反交叉时，PL强度会突然下降。这种效应是NV中心独特的量子特性，在金刚石晶格中的其他可见域发光色心中无法观察到。
