Scalable quantum logic using engineered spin in diamond

最终，量子信息设备可能是固态组件。本工作包的目的是为建立这样一个基于钻石旋转的单位铺平道路。基于项目期间现有的2个量子比特设备，我们的目标是将量子比特的数量扩展到3-5个，并具有向更大单位扩展的前景。金刚石中基于自旋的系统将采用两种不同类型的相互作用。一方面，在分束器上具有后续光子干涉的自旋光子纠缠允许资源友好的缩放，但限于低温操作。另一方面，电子自旋之间的直接耦合是一种替代方法，它足以使室温操作具有足够的保真度。在本工作包中应选择后一种方式。成功需要对环境的可靠控制以及优化的读出和纳米定位技术。为此，工作包涉及以下目标：1。通过在高纯度同位素工程金刚石材料中注入电子自旋，设计、制造和表征金刚石NV中心自旋量子位的量子寄存器。2.建立纳米级自旋量子位寻址的光学读出技术。3.开发和实施协议和算法，最大限度地利用偶极耦合电子自旋。4.开发和实现协议，允许在由通过磁相互作用耦合的几个电子或核自旋组成的量子寄存器中实现鲁棒的确定性纠缠5。发展量子介面，以在钻石的单自旋与光子之间传递量子资讯。将量子控制技术的全部力量应用于量子位及其环境，以最大限度地提高相干时间。7.开发单次自旋的投影、高保真读出（量子非破坏测量）

Ultimately a quantum information device is likely to be a solid state component. It is the aim of this work package to pave the way towards such a unit based on spins in diamond. Based on existing 2 qubits devices for the project period we aim at extending the number of qubits to 3-5 with the prospect of scaling towards larger units. Scaling spin based systems in diamond will employ two different types of interaction. On the one hand spin photon entanglement with subsequent photon interference on a beam splitter allows for resource friendly scaling but is limited to low temperature operation. On the other hand direct coupling between electrons spins is an altemative which is rebuts enough to allow room temperature operation with sufficient fidelity. It is this latter way which should be chosen in this work package. Success requires reliable control over the environment as well as optimized read out and nanopositioning technology. To this end the workpackage addresses the following objectives:1. To design, fabricate and characterize quantum registers with spin qubits in NV centres in diamond by implantation of electron spins in high purity isotopically engineered diamond materials. 2. To establish optical read out technique allowing addressing spin qubits with nanometer resolution. 3. To develop and implement protocols and algorithms that make maximal use of dipolar coupled electron spins. 4. Develop and realize protocols allowing robust deterministic entanglement in a quantum register consisting of a few electron or nuclear spins coupled via magnetic interactions 5. Develop quantum interface for transfer of quantum information between single spin in diamond and photons 6. To apply the full power of quantum control techniques on qubits and their environment to maximize coherence times. 7. Develop projective, high-fidelity readout (quantum non-demolition measurement) of single spin