Scalable noise estimation with random unitary operators
Scalable noise estimation with random unitary operators
复制标题
DOI：
10.1088/1464-4266/7/10/021
复制
发表时间：
2005-10-01
期刊：
影响因子：
--
通讯作者：
Zyczkowski, K
中科院分区：
文献类型：
--
作者：
Emerson, J;Alicki, R;Zyczkowski, K
我们描述了一个可扩展的随机方法的实验测量的广义的相干量子变换的实现的准确性的特征的quantity。该方法是基于随机酉算子的运动反转。在最简单的情况下，我们的方法可以直接估计平均门保真度。更一般的保真度以保真度损失的普适指数率为特征。在所有情况下，可测量的保真度降低与影响实现的噪声的强度直接相关，由描述非酉动力学的超算子的迹量化。虽然我们的随机协议的可扩展性使其在大型希尔伯特空间中最相关（当量子过程层析成像不可行时），但我们的方法应该立即用于评估在任何原型量子处理设备中可实现的控制程度。通过改变不同的实验安排和误差校正策略，可以确定关于噪声的附加信息。
We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method is based on the motion reversal of random unitary operators. In the simplest case our method enables direct estimation of the average gate fidelity. The more general fidelities are characterized by a universal exponential rate of fidelity loss. In all cases the measurable fidelity decrease is directly related to the strength of the noise affecting the implementation, quantified by the trace of the superoperator describing the non-unitary dynamics. While the scalability of our stochastic protocol makes it most relevant in large Hilbert spaces (when quantum process tomography is infeasible), our method should be immediately useful for evaluating the degree of control that is achievable in any prototype quantum processing device. By varying over different experimental arrangements and error-correction strategies, additional information about the noise can be determined.