Non-local codes for Photonic Fault-Tolerant Architectures

光子在远距离传输量子信息方面具有独特的天然能力，从而实现量子设备的远程连接。虽然这一特性被广泛用于量子通信和网络等应用，但容错方法尚未充分利用它：由于采用了为固态平台开发的底层代码，目前基于融合的方法仅使用最近邻门。这给光子架构带来了不必要的强大限制，解除它可能会带来巨大的性能和架构优势。例如，最近开发的量子LDPC码能够比以前的方法更有效地纠正错误，并使用非局部结构。然而，这些代码的实际容错架构仍然缺失。该项目旨在研究这类新颖的代码，为光子硬件开发一种容错架构，利用非局域性来潜在地显著优于当前的方法，为用光子缩放量子计算开辟新的前景。这项研究将结合分析工作和模拟研究。它将在布里斯托尔大学进行，在3年的课程中，将在尼尔斯玻尔研究所停留一次或多次。

Photons are unique in their natural capability to transmit quantum information over long distances, enabling long-range connectivity of quantum devices. While this property is widely used for applications including quantum ommunication and networking, fault-tolerant approaches have yet to fully exploit it: current fusion-based approaches use only nearest-neighbour gates, owing to the adoption of underlying codes that were developed for solid-state platforms. This has put an unrequired strong limitation on photonic architectures and lifting it could potentially bring enormous performance and architectural benefits. For example, quantum LDPC codes have recently beendeveloped that are able to correct errors much more efficiently than previous approaches and use a non-local structure. Practical fault-tolerant architectures for such codes are however still missing. This project aims at investigating such novel class of codes to develop a fault-tolerant architecture for photonic hardware that exploit non-locality to potentially significantly outperform current approaches, opening new prospects for scaling quantum computing with photons. The research will combine analytical work and simulation studies. It will be conducted at the University of Bristol, with one or more extended stays at the Niels Bohr Institute over the course of the 3 years.