Optical single-electron spin detector.

为了探索量子信息处理中的电子自旋，检测其自旋状态（在某些基础上向上/向下）的能力是必不可少的。虽然在受限系统中有完善的电和光自旋检测方法，但对行进电子的自旋检测技术尚未开发。该项目将开发一种用于行进电子波包的自旋探测技术，这将使单电子波包作为飞行量子比特互连固定量子比特元素，以及产生纠缠光子对成为可能。单电子波包将按需从半导体量子点生成。这些波包将通过量子霍尔边缘态传输到在同一衬底上创建的p型区域。当电子与空穴重新结合时，将产生光子，它们的圆极化状态将取决于电子的自旋状态。因此，这项新技术将基于单电子器件技术和由国家物理实验室的量子探测小组和剑桥卡文迪什实验室的半导体物理小组共同开发的横向p-n结。

For the exploration of electron spin in quantum information processing, a capability to detect their spin states (up/down in some basis) is essential. While there are well-established methods for electrical and optical spin detection in confined systems, a spin detection technique for travelling electrons is yet to be developed. This project will develop a spin detection technique for travelling electron wave packets, which would enable the use of single-electron wave packets as flying qubits interconnecting stationary qubit elements, as well as the generation of entangled photon pairs. The single-electron wave packets will be generated, on-demand, from a semiconductor quantum dot. These wave packets will be transported through quantum-Hall edge states to a p-type region created on the same substrate. When the electrons recombine with holes, photons will be generated and their circular polarisation states will depend on the electron spin states. Therefore, this new technology will be based on single-electron device technology and a lateral p-n junction developed jointly by the Quantum Detection Group at NPL and the Semiconductor Physics Group at the Cavendish Laboratory in Cambridge.