The localisation of fluorophores is an important aspect of the determination of the biological function of cellular systems. Quantum correlation microscopy (QCM) is a promising technique for providing diffraction unlimited emitter localisation that can be used with either confocal or widefield modalities. However, so far, QCM has not been applied to three dimensional localisation problems. Here we show that quantum correlation microscopy provides diffraction-unlimited three-dimensional localisation for two emitters within a single diffraction-limited spot. By introducing a two-stage maximum likelihood estimator, our modelling shows that localisation precision scales as $1/\sqrt{t}$ where $t$ is the total detection time. Diffraction unlimited localisation is achieved using both intensity and photon correlation from Hanbury Brown and Twiss measurements at as few as four measurement locations.
Ultimate quantum sensitivity in the 3D relative localisation of two single-photon emitters via two-photon interference
School of Mathematics and Physics, University of Portsmouth（朴茨茅斯大学数学与物理学院）；Institute of Cosmology and Gravitation, University of Portsmouth（朴茨茅斯大学宇宙学与引力研究所）
Towards Quantum Limited Spatial Resolution of NV-Diamond Magnetometry
Wyant College of Optical Sciences, University of Arizona（亚利桑那大学怀特光学学院）；Electrical and Computer Engineering, University of Maryland（马里兰大学电气与计算机工程系）；Department of Electrical Engineering, Indian Institute of Technology Bombay（印度孟买理工学院电气工程系）
The University of Queensland（昆士兰大学）；ARC Centre of Excellence in Quantum Biotechnology（量子生物技术卓越中心）；Queensland Brain Institute（昆士兰大脑研究所）；RMIT University（皇家墨尔本理工大学）；University of Otago（奥塔哥大学）
Deterministic coupling of a quantum emitter to surface plasmon polaritons, Purcell enhanced generation of indistinguishable single photons and quantum information processing
集成光子电路是全光、片上量子信息处理和量子计算机的重要组成部分。纳米等离子体电路中的确定性集成单光子源导致了在衍射极限之外操作的密集封装的可扩展量子逻辑电路。在这里，我们报告的耦合效率的单光子源的等离子体波导，特征传输光谱，传播长度，衰减长度，和等离子体的珀塞尔因子。我们模拟了金属-介质-金属波导中不同宽度介质的透射谱，以找到合适的波长。发现Al $_{2}$ O $_{3}$的最大传输长度为3.98 m，介电宽度为140 nm，耦合效率大于82%.发现等离子体Purcell因子与介电宽度（w）成反比，当w等于1 nm时，其高达31974。我们还计算了光子的量子特性，如不可逆性，发现如果单光子源是确定性耦合的，它可以通过等离子体纳米腔增强。进一步，我们提出了一个可扩展的金属-介质-金属波导基于量子逻辑电路使用的等离子体电路和马赫-曾德尔干涉仪。
