Nature ( IF 42.778 ) Pub Date : 2021-04-07 , DOI: 10.1038/s41586-021-03318-4 J. M. Pino, J. M. Dreiling, C. Figgatt, J. P. Gaebler, S. A. Moses, M. S. Allman, C. H. Baldwin, M. Foss-Feig, D. Hayes, K. Mayer, C. Ryan-Anderson, B. Neyenhuis
The trapped-ion quantum charge-coupled device (QCCD) proposal1,2 lays out a blueprint for a universal quantum computer that uses mobile ions as qubits. Analogous to a charge-coupled device (CCD) camera, which stores and processes imaging information as movable electrical charges in coupled pixels, a QCCD computer stores quantum information in the internal state of electrically charged ions that are transported between different processing zones using dynamic electric fields. The promise of the QCCD architecture is to maintain the low error rates demonstrated in small trapped-ion experiments3,4,5 by limiting the quantum interactions to multiple small ion crystals, then physically splitting and rearranging the constituent ions of these crystals into new crystals, where further interactions occur. This approach leverages transport timescales that are fast relative to the coherence times of the qubits, the insensitivity of the qubit states of the ion to the electric fields used for transport, and the low crosstalk afforded by spatially separated crystals. However, engineering a machine capable of executing these operations across multiple interaction zones with low error introduces many difficulties, which have slowed progress in scaling this architecture to larger qubit numbers. Here we use a cryogenic surface trap to integrate all necessary elements of the QCCD architecture—a scalable trap design, parallel interaction zones and fast ion transport—into a programmable trapped-ion quantum computer that has a system performance consistent with the low error rates achieved in the individual ion crystals. We apply this approach to realize a teleported CNOT gate using mid-circuit measurement6, negligible crosstalk error and a quantum volume7 of 26 = 64. These results demonstrate that the QCCD architecture provides a viable path towards high-performance quantum computers.
中文翻译:

捕获离子量子CCD计算机体系结构的演示
俘获离子量子电荷耦合器件(QCCD)建议1,2列出了使用移动离子作为量子位的通用量子计算机的蓝图。类似于电荷耦合器件(CCD)相机,它以耦合像素中的可移动电荷的形式存储和处理成像信息,而QCCD计算机则以带电离子的内部状态存储量子信息,带电离子通过动态电荷在不同处理区域之间传输领域。QCCD体系结构的承诺是保持在小型俘获离子实验中证明的低错误率3,4,5通过将量子相互作用限制为多个小离子晶体,然后将这些晶体的组成离子物理拆分并重新排列为新的晶体,在其中发生进一步的相互作用。该方法利用了相对于量子位相干时间,离子的量子位态对用于传输的电场的不敏感性以及空间分离的晶体提供的低串扰相对较快的传输时间尺度。但是,设计能够跨多个交互区域以低错误执行这些操作的机器会带来许多困难,这减慢了将该体系结构扩展为更大的量子位数量的进度。在这里,我们使用低温表面陷阱来集成QCCD架构的所有必要元素,即可扩展的陷阱设计,并行相互作用区和快速离子传输—进入可编程俘获离子量子计算机,该计算机具有与单个离子晶体中实现的低错误率一致的系统性能。我们采用这种方法使用中间电路测量来实现瞬态CNOT门如图6所示,串扰误差可忽略不计,量子体积7为2 6 =64。这些结果表明,QCCD体系结构为通往高性能量子计算机提供了一条可行的途径。