论文标题
魔术子空间开放量子系统的纯度速度限制
Purity Speed Limit of Open Quantum Systems from Magic Subspaces
论文作者
论文摘要
我们介绍了魔术子空间的概念，以控制耗散n级量子系统，该系统的动态受lindblad方程的控制。对于给定的纯度，可以将这些子空间定义为一组密度矩阵，其纯度变化速率最大或最小。在系统中添加虚拟的控制字段，以便可以在很短的时间内连接两个密度的操作员，我们表明魔术子空间允许得出纯度速度限制，这仅取决于放松率。我们强调了该限制在建立界限及其紧密性方面的优势，在两级耗散量子系统的情况下。在本研究的框架中讨论了速度限制与相应的时间优化解决方案之间的联系。描述了针对两级和三级量子系统的明确示例。
We introduce the concept of Magic Subspaces for the control of dissipative N- level quantum systems whose dynamics are governed by Lindblad equation. For a given purity, these subspaces can be defined as the set of density matrices for which the rate of purity change is maximum or minimum. Adding fictitious control fields to the system so that two density operators with the same purity can be connected in a very short time, we show that magic subspaces allow to derive a purity speed limit, which only depends on the relaxation rates. We emphasize the superiority of this limit with respect to established bounds and its tightness in the case of a two-level dissipative quantum system. The link between the speed limit and the corresponding time-optimal solution is discussed in the framework of this study. Explicit examples are described for two- and three- level quantum systems.
