论文标题
系统子空间的时间演变的量子速度限制
Quantum speed limits for time evolution of a system subspace
论文作者
论文摘要
量子状态的时间演变的基本限制之一是以著名的Mandelstam-Tamm不平等的形式知道的。这种不平等问题回答了一个问题，即孤立的量子系统可以从其初始状态发展到正交状态的问题。反过来，Fleming Bound是Mandelstam-Tamm不平等的扩展，它为非正交初始状态和最终状态之间的演变提供了最佳速度。在目前的工作中，我们不关心单个状态，而是在系统状态的整体（可能是无限的）子空间（可能是无限的）子空间。通过使用子空间之间的最大角度的概念，我们得出了对这种子空间进化速度的最佳估计，该速度可能被视为弗莱明结合的自然概括。
One of the fundamental physical limits on the speed of time evolution of a quantum state is known in the form of the celebrated Mandelstam-Tamm inequality. This inequality gives an answer to the question on how fast an isolated quantum system can evolve from its initial state to an orthogonal one. In its turn, the Fleming bound is an extension of the Mandelstam-Tamm inequality that gives an optimal speed bound for the evolution between non-orthogonal initial and final states. In the present work, we are concerned not with a single state but with a whole (possibly infinite-dimensional) subspace of the system states that are subject to the Schroedinger evolution. By using the concept of maximal angle between subspaces we derive an optimal estimate on the speed of such a subspace evolution that may be viewed as a natural generalization of the Fleming bound.
