中文摘要：

文献[Quantum Information and Computation，2005，5（4）：350—363]提出量子相干性跟踪控制策略以保持量子位的相干性，该策略本质是开环控制，而开环控制的缺陷就是严重依赖于精确地了解系统的初始条件和模型参数。然而，我们对于系统的知识总是存在不确定性的。本文从鲁棒性的角度分析了量子相干性跟踪控制策略的局限性。首先，我们对该方法的鲁棒性进行了理论分析；接着用仿真实例定量说明了：量子初始条件和模型参数的精度对保持相干性的影响。根据相干性的精度要求，我们可以利用仿真分析的手段，来确定对模型参数和初始状态必须满足的精度条件。总之，我们在应用中必须谨慎采用量子相干性跟踪控制策略。

英文摘要：

The scheme of quantum coherence tracking control was presented in [ Quantum Information and Computation,2005,5 （4） ：350-363 ] to control the quantum coherence. That scheme is essentially an openloop control method, whose disadvantage is that it depends seriously on the precise knowledge of the initial conditions and model parameter. Unfortunately, the uncertainty of the knowledge about physical system can not be avoided in application. This paper shows the limitation of quantum coherence tracking control from the viewpoint of robustness. Firstly, the theoretical analysis is given in detail. Subsequently, simulation examples are presented to quantitatively illustrate that how the coherence tracking control is subject to the precision of the initial condition and the model parameter. According to the requirement of the precision of coherence, we can employ the simulation methods to get the necessary condition on the precison of model parameter and initial state. In a word, quantum coherence tracking control methods need to be used modestly in application.