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arXiv 1407.6502quant-ph
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两电平系统的高速驱动

High-Speed Driving of a Two-Level System

Gerhard C. Hegerfeldt

摘要:

一个非常简单的结果被发现的最佳协议的驱动一般两个层次的哈密顿运输一个给定的初始状态到一个给定的最终状态在最短的时间。如果三个可能的驱动之一是不受约束的强度问题是完全解析解决。当一个驱动被常数$c$限制而其他驱动是常数时,一类状态会出现令人惊讶的情况。然后,对于大的$c$,最优驱动是bang-off-bang类型,并且对于增大的$c$,恢复无约束结果。然而,对于较小的$c$,最佳驱动可以突然切换到开关式。它还表明,对于一般状态,可以有一个多步骤的协议。本文明确证明并大大扩展了作者在物理评论快报中的结果。{ \bf 111},260501(2013)。

英文摘要:

A remarkably simple result is found for the optimal protocol of drivings for a general two-level Hamiltonian which transports a given initial state to a given final state in minimal time. If one of the three possible drivings is unconstrained in strength the problem is analytically completely solvable. A surprise arises for a class of states when one driving is bounded by a constant $c$ and the other drivings are constant. Then, for large $c$, the optimal driving is of type bang-off-bang and for increasing $c$ one recovers the unconstrained result. However, for smaller $c$ the optimal driving can suddenly switch to bang-bang type. It is also shown that for general states one may have a multistep protocol. The present paper explicitly proves and considerably extends the author's results contained in Phys. Rev. Lett. {\bf 111}, 260501 (2013).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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