Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States.
J Phys Chem B. 2011 May 12;115(18):5234-42. doi: 10.1021/jp108331x. Epub 2011 Mar 9.
A general coherent control scenario to suppress or accelerate tunneling of quantum states decaying into a continuum is investigated. The method is based on deterministic, or stochastic, sequences of unitary pulses that affect the underlying interference phenomena responsible for quantum dynamics, without inducing decoherence, or collapsing the coherent evolution of the system. The influence of control sequences on the ensuing quantum dynamics is analyzed by using perturbation theory to first order in the control pulse fields and compared to dynamical decoupling protocols and to sequences of pulses that collapse the coherent evolution and induce quantum Zeno (QZE) or quantum anti-Zeno effects (AZE). The analysis reveals a subtle interplay between coherent and incoherent phenomena and demonstrates that dynamics analogous to the evolution due to QZE or AZE can be generated from stochastic sequences of unitary pulses when averaged over all possible realizations.
研究了一种通用的相干控制方案，以抑制或加速衰减到连续体的量子态的隧穿。该方法基于确定性或随机的幺正脉冲序列，这些序列影响导致量子动力学的基础干涉现象，而不会引起退相干或破坏系统的相干演化。通过使用微扰理论对控制脉冲场进行一阶近似，将控制序列对随后的量子动力学的影响与动态去耦协议以及破坏相干演化并诱导量子 Zeno（QZE）或量子反 Zeno 效应（AZE）的脉冲序列进行了比较。分析揭示了相干和非相干现象之间的微妙相互作用，并证明了当在所有可能的实现上平均时，可以从幺正脉冲的随机序列中产生类似于 QZE 或 AZE 引起的演化的动力学。
