Quantum interface engineering with solid-state spins and photons

固态自旋和光子的量子界面工程

• 批准号: 2742534
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2742534
• 关键词: Quantum; interface; engineering; solid; state

This project falls within the EPSRC "quantum technologies" research area. The project focuses on experimental quantum communication technologies, using in particular III-V quantum dots (QDs), which are widely considered to be amongst the leading quantum node candidates for use in quantum optical networks. It will investigate a new generation of lattice-matched GaAs QDs, which promise a major improvement in the coherence properties of spin quantum bits (qubits) relative to the state of the art in self-assembled InGaAs QDs. The overall objective is to demonstrate that they can serve as a quantum networking node, which requires showing simultaneously: high-efficiency photon collection, qubit control, and a nuclear quantum memory. This will allow the generation of photons from the QD which are entangled with its solid-state spin qubits for a sufficient time that they can be used to network with other quantum nodes to realize a quantum network.Initially the focus will be on improving the optical interface between the spin qubits in the QDs and the outgoing photons. Enhancing photon collection efficiency is crucial, as while GaAs QDs have shown great promise in terms of their long spin coherence times, an important metric for preserving the quantum state, they lag other QD candidates (e.g. InGaAs) in terms of photon collection efficiency. The vision is to place the quantum emitter (QD) into a photonic microcavity, which would enhance emission and coupling into a fibre mode for long distance transmission. Next, we will demonstrate qubit control of the QD electron spin, which will be performed all-optically. This combination of spin control within an efficient optical interface will be unique, and will allow proof-of-concept demonstrations such as a deterministic photon-photon quantum gate. Finally, a quantum memory will be made possible by capitalizing on the hyperfine interaction between the single electron and the proximal nuclear spins to facilitate an optically addressable memory using the electron, enabling this QD-based quantum node to have dedicated quantum memories. The project aims to deliver benchmarking results on a multitude of quantum protocols forming the backbone of a quantum communication and computing network, such as quantum gates between photon qubits, generation of quantum repeater states, and distribution and storage of entanglement. Realizing a viable quantum optical network would enable a truly quantum internet between quantum nodes, paving the way for fully private communications (ensured by the principles of quantum mechanics), quantum cryptography, and distributed quantum computing. The work is performed in collaboration with the Quantum Optical Materials and Systems group at the University of Cambridge, the Semiconductor Physics group at Johannes Kepler University Linz, and the Photonic Nanomaterials Group at the University of Oxford.

该项目属于EPSRC“量子技术”研究领域。该项目的重点是使用尤其是III-V量子点（QD）的实验量子通信技术，这些数据被广泛认为是用于量子光学网络中的领先量子节点候选者之一。它将研究新一代的晶格匹配的GAAS QD，该QD有望在自组装的Ingaas QD中相对于自旋量子位（Qubits）的相干性（Qubits）的相干性能有所改善。总体目标是证明它们可以用作量子网络节点，该节点需要同时显示：高效光子收集，量子控制和核量子记忆。这将允许从QD中产生与固态自旋矩形纠缠的光子，以使它们可以与其他量子节点联系起来，以实现量子网络。从本质上讲，焦点将放在改善QDS和即将出现的光子之间的旋转量表之间的光学界面。提高光子收集效率至关重要，就像GAAS QD在其长期旋转相干时表现出巨大的希望，这是保留量子状态的重要指标，但它们在光子收集效率方面滞后其他QD QD候选者（例如INGAAS）。视力是将量子发射极（QD）放入光子微腔，这将增强发射并耦合到纤维模式中以进行长距离传播。接下来，我们将展示QD电子自旋的量子控制，该QD电子自旋将全面执行。在有效的光学接口中自旋控制的这种组合将是唯一的，并且将允许概念验证演示，例如确定性光子 - 光子量子门。最后，通过利用单电子和近端核自旋之间的超精细相互作用来实现量子记忆，从而使用电子中促进光学上可寻址的存储器，从而使该基于QD的量子节点具有专用的量子记忆。该项目旨在在构成量子通信和计算网络的骨架的多种量子协议上提供基准测试结果，例如光子量子矩阵之间的量子门，量子中继器状态的产生以及纠缠的分布和存储。实现可行的量子光学网络将使量子节点之间真正的量子互联网，为完全私人通信（通过量子力学原理确保），量子加密和分布式量子计算铺平了道路。这项工作是与剑桥大学的量子光学材料和系统组合作进行的，约翰内斯·开普勒大学的半导体物理小组以及牛津大学的光子纳米材料组。