研究了混态粒子的纯度补偿以及消相干过程的抵消问题，提出了利用辅助粒子及其与目标粒子的相互作用进行纯度及相干性补偿的方法。给出了2种不同情况——混态目标粒子的纯度补偿和消相干过程的抵消——辅助粒子的充要条件。并通过系统数值仿真实验验证了所设计方法的有效性。

In this paper, problems of compensation for purity of particle in a mixed state and counteraction against decoherence process are investigated. A new method utilizing an assistant particle and its interactions with the target particle to compensate purity and coherence is proposed. Compensations for two different situations are considered: purity compensation for the target particle in a mixed state and counteraction against decoherence process. Conditions of the assistant particle for each situation are obtained. System numerical simulations are done to validate the validity of the method proposed.