Robust Majorana magic gates via measurements
Robust Majorana magic gates via measurements
复制标题
DOI：
10.1103/physrevb.99.144521
复制
发表时间：
2018-12
影响因子：
3.7
通讯作者：
Torsten Karzig;Y. Oreg;G. Refael;M. Freedman
中科院分区：
文献类型：
--
作者：
Torsten Karzig;Y. Oreg;G. Refael;M. Freedman
π/8相位门（魔门或T门）是将基于马约拉纳零模的拓扑系统增强到完全量子普适性的关键。我们提出了一个计划的基础上结合投影测量和非绝热演化，有效地取消平滑控制误差时，在基于马约拉纳的系统中实现相位门。以前的计划的基础上绝热演化容易受到问题所产生的小，但有限的动力学阶段，一般存在于拓扑不受保护的门。仅测量的方法消除了动态相位。然而，对于不受保护的门，强制测量方案不再有效，这导致在仅测量实现中获得正确的连续测量结果的成功概率较低。我们展示了如何获得一个可行的测量为基础的计划，大大增加了成功的概率，通过不断发展的系统相对于测量之间的退化子空间。我们概述了我们的计划在最近提出的量子计算设计的基础上马约拉纳四重子和六重子的实际应用。
π/8 phase gates (magic gates or T gates) are crucial to augment topological systems based on Majorana zero modes to full quantum universality. We present a scheme based on a combination of projective measurements and nonadiabatic evolution that effectively cancels smooth control errors when implementing phase gates in Majorana-based systems. Previous schemes based on adiabatic evolution are susceptible to problems arising from small but finite dynamical phases that are generically present in topologically unprotected gates. A measurement-only approach eliminates dynamical phases. For nonprotected gates, however, forced-measurement schemes are no longer effective, which leads to low success probabilities of obtaining the right succession of measurement outcomes in a measurement-only implementation. We show how to obtain a viable measurement-based scheme which dramatically increases the success probabilities by evolving the system nonadiabatically with respect to the degenerate subspace in between measurements. We outline practical applications of our scheme in recently proposed quantum computing designs based on Majorana tetrons and hexons.