Interfacing solid state single emitters with atomic quantum memories

单有机分子，如二苯并甲苯（DBT）是单光子的优秀固态源。它们的发射波长与铷中的电子跃迁一致（780 ~ 795 nm），低温下的发射线宽达到寿命极限（40 MHz）。因此，使用DBT产生的光子与使用冷热原子系综的各种量子存储协议兼容。本博士项目将研究增强DBT分子发射和提高单分子光子后续收集效率的途径。为了做到这一点，我将进行纳米光子建模和制造，以制造波导和腔结构。这些将在低温下使用共聚焦显微镜和激光荧光光谱进行表征。同时，我将开发在铷中演示量子存储器协议所需的设备。这将包括模拟量子存储器，建立温暖的原子蒸汽装置，建立磁光阱系统来产生原子冷云，以及使用激光的快速强度调制来产生存储和检索光子所需的光脉冲。将研究几种存储协议，包括电磁感应透明，奥特勒-汤斯分裂，非共振级联吸收和拉曼记忆。然后，我将把分子和原子实验结合在一起，演示使用原子蒸汽的单个分子产生的光子的存储和检索。此外，原子频率转换方案将被研究，以允许有效地转换到电信波段的光子，从而使在布里斯托尔大学校园内进行纠缠交换成为可能。

Single organic molecules such as dibenzoterrylene (DBT) are excellent solid-state sources of single photons. Their emission wavelength coincides with electronic transitions in rubidium (780 - 795 nm) and emission linewidths at low temperature reach the lifetime limit (40 MHz). As such the photons generated using DBT are compatible with various quantum memory protocols using both warm and cold atomic ensembles. This PhD project will investigate routes to enhancing the emission of DBT molecules and increasing the subsequent collection efficiency of photons from single molecules. To do this I will perform nanophotonic modelling and fabrication to make waveguide and cavity structures. These will then be characterized at cryogenic temperature using confocal microscopy and laser fluorescence spectroscopy. Meanwhile, I will develop the apparatus required to demonstrate quantum memory protocols in rubidium. This will involve modelling the quantum memory, building warm atomic vapour setups, building a magneto-optical trap system to create cold clouds of atoms, and using fast intensity modulation of lasers to create the optical pulses needed to store and retrieve photons. Several memory protocols will be investigated including electromagnetically induced transparency, Autler-Townes splitting, off-resonant cascaded absorption, and Raman memories. I will then combine the molecule and atom experiments together to demonstrate the storage and retrieval of photons generated using a single molecule using an atomic vapour. In addition, atomic frequency conversion schemes will be investigated to allow for efficient conversion to telecommunication band photons to enable the possibility of an entanglement swapping across the University of Bristol campus.