We present an architecture for encoding two qubits within the optical “clock” transition and nuclear spin-1/2 degree of freedom of neutral ytterbium-171 atoms. Inspired by recent high-fidelity control of all pairs of states within this four-dimensional quotes space, we present a toolbox for intra-ququart (single-atom) one- and two-qubit gates, inter-ququart (two-atom) Rydberg-based two- and four-qubit gates, and quantum nondemolition (QND) readout. We then use this toolbox to demonstrate the advantages of the ququart encoding for entanglement distillation and quantum error correction which exhibit superior hardware efficiency and better performance in some cases since fewer two-atom operations are required. Finally, leveraging single-state QND readout in our ququart encoding, we present a unique approach to studying interactive circuits and to realizing a symmetry protected topological phase of a spin-1 chain with a shallow, constant-depth circuit.

我们提出了一种架构，用于在中性镱 171 原子的光学“时钟”跃迁和核自旋 1/2 自由度内编码两个量子比特。受最近对这个四维引用空间内所有状态对的高保真控制的启发，我们提出了一个用于 intra-ququart（单原子）单量子比特和双量子比特门、inter-ququart（双原子）基于 Rydberg 的双量子比特和四量子比特门以及量子非破坏 （QND） 读出的工具箱。然后，我们使用此工具箱来演示 ququart 编码在纠缠蒸馏和量子纠错方面的优势，这些优势在某些情况下表现出卓越的硬件效率和更好的性能，因为需要的双原子操作更少。最后，利用 ququart 编码中的单态 QND 读出，我们提出了一种独特的方法来研究交互式电路，并通过浅的恒定深度电路实现 spin-1 链的对称保护拓扑相位。