Department of Physics, Harvard University, Cambridge, MA, USA.
AWS Center for Quantum Computing, Pasadena, CA, USA.
Nature. 2022 Apr;604(7906):451-456. doi: 10.1038/s41586-022-04592-6. Epub 2022 Apr 20.
The ability to engineer parallel, programmable operations between desired qubits within a quantum processor is key for building scalable quantum information systems. In most state-of-the-art approaches, qubits interact locally, constrained by the connectivity associated with their fixed spatial layout. Here we demonstrate a quantum processor with dynamic, non-local connectivity, in which entangled qubits are coherently transported in a highly parallel manner across two spatial dimensions, between layers of single- and two-qubit operations. Our approach makes use of neutral atom arrays trapped and transported by optical tweezers; hyperfine states are used for robust quantum information storage, and excitation into Rydberg states is used for entanglement generation. We use this architecture to realize programmable generation of entangled graph states, such as cluster states and a seven-qubit Steane code state. Furthermore, we shuttle entangled ancilla arrays to realize a surface code state with thirteen data and six ancillary qubits and a toric code state on a torus with sixteen data and eight ancillary qubits. Finally, we use this architecture to realize a hybrid analogue-digital evolution and use it for measuring entanglement entropy in quantum simulations, experimentally observing non-monotonic entanglement dynamics associated with quantum many-body scars. Realizing a long-standing goal, these results provide a route towards scalable quantum processing and enable applications ranging from simulation to metrology.
在量子处理器中对所需量子位进行并行、可编程操作的能力是构建可扩展量子信息系统的关键。在大多数最先进的方法中,量子位局部相互作用,受到与其固定空间布局相关的连接性的限制。在这里,我们展示了一种具有动态、非局部连接性的量子处理器,其中纠缠量子位以高度并行的方式在两个空间维度之间相干传输,跨越单量子位和双量子位操作的两层。我们的方法利用了被光学镊子捕获和传输的中性原子阵列;超精细状态用于稳健的量子信息存储,激发到里德堡态用于纠缠生成。我们使用这种架构来实现可编程生成纠缠图态,例如簇态和七量子位斯泰恩码态。此外,我们还利用纠缠辅助阵列来实现具有 13 个数据和 6 个辅助量子位的表面码态,以及具有 16 个数据和 8 个辅助量子位的环面码态。最后,我们使用这种架构来实现混合模拟-数字演化,并将其用于量子模拟中的纠缠熵测量,实验观察到与量子多体疤痕相关的非单调纠缠动力学。实现了一个长期以来的目标,这些结果为可扩展的量子处理提供了一条途径,并为从模拟到计量学的各种应用开辟了道路。