论文标题
循环管道可在严格的2D设备中实现有效的3D Qubit晶格
Looped Pipelines Enabling Effective 3D Qubit Lattices in a Strictly 2D Device
论文作者
论文摘要
许多量子计算平台基于二维物理布局。在这里,我们探索了一个称为循环管道的概念,该概念允许在操作严格的2D设备时获得3D晶格的许多优势。该概念利用Qubit Shuttling,这是半导体旋转量子和捕获量子尺等平台中的一个完善的功能。循环管道体系结构具有与其他穿梭方法相似的硬件要求,但是可以处理一堆Qubit阵列,而不仅仅是一个。即使是一堆有限的高度,也可以实现从NISQ时代的误差到耐故障代码的各种方案。对于前者,可以使用涉及多个状态的协议以与准备一份嘈杂副本相当的时空资源成本实施。对于后者,人们可以实现多种多样的代码结构。作为示例,我们考虑了分层的2D代码,其中可用横向CNOT。在合理的假设下,这种方法可以将魔术状态蒸馏的时空成本降低两个数量级。使用实验动机的噪声模型进行数值建模验证了该体系结构在没有大幅度降低代码阈值的情况下提供了此优势。
Many quantum computing platforms are based on a two-dimensional physical layout. Here we explore a concept called looped pipelines which permits one to obtain many of the advantages of a 3D lattice while operating a strictly 2D device. The concept leverages qubit shuttling, a well-established feature in platforms like semiconductor spin qubits and trapped-ion qubits. The looped pipeline architecture has similar hardware requirements to other shuttling approaches, but can process a stack of qubit arrays instead of just one. Even a stack of limited height is enabling for diverse schemes ranging from NISQ-era error mitigation through to fault-tolerant codes. For the former, protocols involving multiple states can be implemented with a space-time resource cost comparable to preparing one noisy copy. For the latter, one can realise a far broader variety of code structures; as an example we consider layered 2D codes within which transversal CNOTs are available. Under reasonable assumptions this approach can reduce the space-time cost of magic state distillation by two orders of magnitude. Numerical modelling using experimentally-motivated noise models verifies that the architecture provides this benefit without significant reduction to the code's threshold.