The relation between external control field and its acting time is also discussed. The result shows that the acting time is in inverse proportion to control strength in some certain period when a quantum control task is given.

• 讨论了外部控制场与其作用时间的关系；结果表明:对于给定的量子控制任务；在选定的某个周期内；作用时间与控制场强度成反比.