Author Affiliations
Abstract
1 School of Physics, East China University of Science and Technology, Shanghai 200237, China
2 Shanghai Engineering Research Center of Hierarchical Nanomaterials, Shanghai 200237, China
3 Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai 200237, China
Nitrogen-vacancy (NV) centers in diamond are progressively favored for room-temperature magnetic field measurement. The signal to noise ratio (SNR) optimization for NV diamond magnetometry generally concentrates on signal amplitude enhancement rather than efficient noise processing. Here, we report a compound filter system combining a wavelet denoising method and an adaptive filter for the realization of an efficient weak magnetic measurement with a high SNR. It allows enhanced magnetic field measurement with an average SNR enhancement of 17.80 dB at 50 nT within 500 mHz to 100 Hz and 14.76 dB at 500 mHz within 50 nT to 1100 nT. The introduction of this system in NV diamond magnetometry is aimed to improve signal quality by effectively eliminating the noise and retaining ideal signals.
nitrogen-vacancy center quantum sensing signal processing Chinese Optics Letters
2023, 21(11): 111201
Author Affiliations
Abstract
1 CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
2 CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
3 Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
Modulation of a vector light field has played an important role in the research of nanophotonics. However, it is still a great challenge to accurately measure the three-dimensional vector distribution at nanoscale. Here, based on the interaction between the light field and atomic-sized nitrogen-vacancy (NV) color center in diamonds, we demonstrate an efficient method for vectorial mapping of the light-field distribution at nanoscale. Single NV centers with different but well-defined symmetry axes are selected and then interact with the same tightly focused light field. The excitation of a single NV center is related to the angle between the NV center axis and the polarization of the light field. Then the fluorescence patterns of different NV centers provide the information on the vectorial light field distribution. Subsequently analyzing the fluorescence patterns with the help of a deep neural network, the intensity and phase of the light-field vectorial components are fully reconstructed with nanometer resolution. The experimental results are in agreement with theoretical calculations. It demonstrates that our method can help to study light–matter interaction at nanoscale and extend the application of vector light fields in research on nanophotonics.
light-field measurement nitrogen-vacancy center tightly focused light field Chinese Optics Letters
2023, 21(7): 071202
1 北京科技大学新材料技术研究院，北京 100083
2 中国科学院高能物理研究所核探测与核电子学国家重点实验室，北京 100049
3 东莞中子科学中心，广东 东莞 523800
采用高能电子辐照结合真空退火，在金刚石内部形成氮空位色心。对比研究了辐照与退火前后金刚石宏观颜色变化及内部缺陷转变，讨论了不同辐照剂量和真空退火温度对氮空位产率的影响规律。结果显示，氮空位色心浓度随着辐照剂量的增加呈现先升高后降低的趋势，这是由于辐照剂量越高则空位更容易形成空位簇，空位簇在退火过程中不能形成氮空位色心。氮空位色心浓度随退火温度的升高逐渐增加，在800~900 ℃区间达到饱和，当温度继续升高时，氮空位色心浓度反而下降，这源于辐照过程产生的间隙原子在高温下与氮空位的相互作用。
光学器件 氮空位色心 金刚石 电子辐照 退火 光学学报
2022, 42(13): 1316001
1 南京邮电大学 通信与信息工程学院，江苏 南京 210003
2 宿迁学院 机电工程学院，江苏 南京 223865
随着单片微波集成电路(MMIC)集成度和复杂度的提高，芯片功能模块之间的距离越来越近，特征线宽越来越窄，对于分析芯片内部的信号路径和信号的完整性，能够提供芯片表面的高分辨微波场成像显得尤为重要。为了解决准确检测芯片内部结构完整无损的问题，这项工作采用了一种基于光纤的近场扫描探头的方法，其中包含氮空位(NV)色心的金刚石颗粒固定在光纤的尖端，通过搭建光路并接收金刚石NV色心的荧光信号，从而推理出被测芯片的磁场强度。该实验选取一个微波低噪声放大器芯片内部的区域进行扫描成像，得到了较好的成像结果，并准确分析出芯片的信号线走势。这些结果为高度集成芯片和滤波器等集成器件的功能和失效分析提供了变革性的方法。
单片微波集成电路 微波场 金刚石探头 氮空位色心 Monolithic Microwave Integrated Circuit microwave field diamond probe Nitrogen Vacancy center 太赫兹科学与电子信息学报
2021, 19(5): 901
合肥工业大学电子科学与应用物理学院 安徽 合肥 230009
场矢量探测是量子精密测量的重要分支, 在基础物理、生物医学、材料科学等领域, 都有着广泛的应用。金刚石氮- 空穴(Nitrogen-Vacancy Center)色心作为量子传感器, 在室温下具有较长相干时间, 可以实现纳米尺度的磁场探测。为了实现纳米分辨率的磁场重构, 需要选取金刚石中三个不同轴向的NV色心作为磁场传感器。实验上能否快速和精确地获得NV色心的轴向信息直接决定着矢量磁场测量的精度和效率。本文利用角向偏振光束代替高斯光束激发NV色心获得其扫描荧光图像, 结合卷积神经网络对NV色心的荧光图像进行识别, 提出了一种基于图像匹配的NV色心拟合优化算法, 在梯度下降算法上结合图像识别处理和匹配算法, 优化了NV色心轴向信息的提取过程, 提高了拟合的速度和准确率, 进而增加了磁场矢量重构的效率。
金刚石氮- 空穴色心 回程差消除 图像匹配 目标检测 色心轴向识别 nitrogen-vacancy center elimination of backhaul difference image matching object detection axial recognition
Author Affiliations
Abstract
1 CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
2 CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
3 Hefei National Laboratory for Physical Science at Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026, China
The nitrogen vacancy (NV) center in diamond has been well applied in quantum sensing of electromagnetic field and temperature, where the sensitivity can be enhanced by the number of NV centers. Here, we used electron beam irradiation to increase the generation rate of NV centers by nearly 22 times. We systematically studied the optical and electronic properties of the NV center as a function of an electron irradiation dose, where the detection sensitivity of magnetic fields was improved. With such samples with dense NV centers, a sub-pico-Tesla sensitivity in magnetic fields detection can be achieved with optimal controls and detections.
quantum sensing nitrogen vacancy center generation electron irradiation Chinese Optics Letters
2020, 18(8): 080201
山西工程技术学院 基础部,山西 阳泉 045000
量子信息学作为一门新兴学科引起了科学家的关注,量子逻辑门是量子信息处理的关键结构。在本文中,我们提出基于金刚石氮-空位中心的偶极诱导透明(DIT)过程,这个金刚石氮-空位中心囚禁于一个耦合到两个波导的光子晶体腔。在Purcell体系中,对于非耦合腔和耦合腔的圆极化光的反射率和透射率的差异是鲁棒且可调的,这说明DIT是明显的。利用该DIT,我们实现了空间极化超CNOT门。在多个自由度的量子比特系统的量子信息协议中它们可以用更少的资源来执行更多的量子操作,这样可以减少能量损耗和光子耗散。
偶极诱导透明 量子逻辑门 金刚石氮-空位中心 dipole induced transparency quantum logic gate nitrogen-vacancy center
1 中国人民解放军63892部队, 河南 洛阳 471003
2 中国科学院物理研究所固态量子信息与计算实验室, 北京 100790
金刚石中单个氮空位中心的电子自旋在激光辐射下能够发出近红外的光致荧光,增加微波辐射可以对其进行量子调控,是室温条件下实现量子计算机的主要介质之一。本文利用激光共聚焦扫描显微系统观测到了金刚石晶体中氮空位中心的荧光二维扫描图,并通过二次相关函数测量验证了氮空位中心是单光子源。改变微波辐射频率得到了电子自旋共振谱,从而实现了对单个氮空位中心的量子调控。利用设计的可控静磁场研究了氮空位中心在不同磁场方向和大小时的光致荧光特性和自旋共振峰。实验结果表明两个电子自旋共振峰间的频率间距与静磁场的旋转角度成余弦函数关系,与理论分析结果一致。
金刚石 氮空位中心 量子调控 电子自旋共振 diamond nitrogen vacancy center quantum manipulation electron spin resonance
