Opto-Spintronic interfaces for next generation quantum networks - (SpinNet)

量子计算正在成为一个迅速成熟的领域，加速了对新技术的需求，这些新技术可以使分布式量子信息创建量子计算机网络。这种量子网络或量子互联网有望提供前所未有的能力，并使我们能够执行当今网络无法执行的任务。虽然更安全的网络将是量子互联网的首批应用之一，但将量子设备连接在一起将对我们如何执行其他几项任务产生破坏性和变革性的影响。例如，届时将有可能解决目前使用经典计算机甚至使用单个量子计算机无法实现的问题，包括在天文学，材料发现，超导量子比特--在微波频率下工作--是当今世界的核心，领先的量子计算平台，现在作为包括几十个量子比特的原型量子计算机的基础。近年来，量子计算的其他架构也引起了人们的极大兴趣，例如半导体自旋量子比特，以及最近（就在去年）提出的在人工冰中使用磁单极子的更复杂的系统，作为量子信息处理的一条令人兴奋的路线。然而，无论是基于超导还是基于自旋，量子比特的微波信号都是实现大规模量子信息分布的关键障碍，因为它们对热噪声非常敏感，并且/或者信号频率在微波波段。因此，阻止了量子信号的长距离传播，并使其不适用于网络微波量子计算机。在这里，我们建议开发一种保持纠缠的微波量子比特到光学量子比特接口，这将允许量子态在数千米的光纤电缆或通过自由空间通道上分布。实现这样的接口对于形成全球量子计算机网络的基础和实现真正的量子互联网至关重要。

Quantum computing is becoming a rapidly maturing field, hastening the need for novel technologies that can enable distributed quantum information to create quantum computer networks. Such quantum network, or quantum internet, is expected to offer unprecedented capabilities as well as enable us to perform tasks that are impossible to carry out with today's web. Whilst a more secure network would be one of the first applications of a quantum internet, connecting quantum devices together will have a disruptive and transformative impact on how we perform several other tasks. For instance, it would then be possible to solve problems that are currently impossible to achieve using classical computers, or even using a single quantum computer, including carrying out large-scale sensing experiments in astronomy, materials discovery, and life sciences without the need for the exchange of vast amounts of data.Superconducting qubits-operating at microwave frequencies-are central to current world-leading quantum computing platforms and now serve as the basis for prototype quantum computers comprising several tens of qubits. Other architectures for quantum computing have also gained significant interest in recent years, such as semiconductor spin qubits and more recently-just last year-more sophisticated systems using magnetic monopoles in artificial ices have been proposed as an exciting route for quantum information processing. Whether superconducting or spin-based, the qubits' microwave signals are, however, a key hurdle in achieving large-scale quantum information distribution as they are extremely susceptible to thermal noise and/or the signal frequencies are in the microwave band. Thus, preventing the propagation of quantum signals over a long distance and making it unviable to network microwave quantum computers. Here, we propose to develop an entanglement-preserving microwave-qubit to-optical qubit interface, that will allow for the distribution of quantum states over many kilometres of fibre optical cables or through free-space channels. Realising such an interface would be critical in forming the basis of a global network of quantum computers and to realise a truly quantum internet.