Application of High-Fidelity, High-Speed Remote Entanglement of Trapped Ion Qubits to Fundamental Quantum Information Processing

捕获离子具有许多有用的特性，使它们成为实现量子算法的合适候选者，例如长相干时间和通过离子的相互库仑排斥以高度可控的方式纠缠它们的能力，这种方式介导了它们之间的耦合。然而，量子比特的数量必须显著增加，才能使量子信息处理与经典计算机竞争。将捕获离子量子处理器扩展到更大量子位的两个最先进的建议，要么依赖于在不同的处理器模块之间物理地穿梭单个离子，要么依赖于光子概率链路。在这方面，作为一名博士生，我的目标是在量子信息研究的科学前沿贡献自己的一份力量，坚持涉及光子概率链路的建议，第一次参与构建一个按比例放大的离子阱量子计算机的挑战。远程捕获离子之间的纠缠方案有待改进。多探测器方案和光纤网络的使用将提高纠缠的保真度。使用纠缠净化技术将允许提取更高保真度的纠缠态，可以用于演示宏观距离上的受控量子动力学，例如双量子位CNOT门。该实验还可以实现状态隐形传态、远程状态制备和密集编码量子信息协议的实现。通过安装增强光纤模式发射的腔体，从而提高光子收集效率，可以提高纠缠产生率。本研究属于量子技术ESPRC研究主题。

Trapped ions have many useful properties that make them a suitable candidate for the implementation of quantum algorithms, such as long coherence times and the ability to entangle them in a highly controllable way through the mutual Coulomb repulsion of the ions that mediates a coupling between them. However, the number of qubits must be significantly increased to render quantum information processing competitive with classical computers. The two most advanced proposals to scale trapped-ion quantum processors to larger numbers of qubits rely either on physically shuttling individual ions between different processor modules or photonic probabilistic links.In this regard, as a doctoral student, I aim to contribute to the progress at the scientific forefront of quantum information research and take part in the challenge to build a scaled-up ion trap quantum computer for the first time, adhering to the proposal involving photonic probabilistic links. Improvements on entanglement schemes between remote trapped ions are to be carried out. The fidelity of entanglement will be enhanced by a multi-detector scheme and using fibre networks. Employing the entanglement purification technique will allow to distil even higher fidelity entangled states that can be used to demonstrate controlled quantum dynamics over macroscopic distances, for example the two-qubit CNOT gate. The experiment might also enable state teleportation, remote state preparation and an implementation of the dense coding quantum information protocol. The entanglement generation rate will be improved by the installation of cavities that enhance the emission into the fibre mode, thereby increasing the photon collection efficiency. This research falls under the Quantum Technologies ESPRC Research Theme.