Publication Date:
2008-05-03
Description:
Manipulation of quantum interference requires that the system under control remains coherent, avoiding (or at least postponing) the phase randomization that can ensue from coupling to an uncontrolled environment. We show that closed-loop coherent control can be used to mitigate the rate of quantum dephasing in a gas-phase ensemble of potassium dimers (K2), which acts as a model system for testing the general concepts of controlling decoherence. Specifically, we adaptively shaped the light pulse used to prepare a vibrational wave packet in electronically excited K2, with the amplitude of quantum beats in the fluorescence signal used as an easily measured surrogate for the purpose of optimizing coherence. The optimal pulse increased the beat amplitude from below the noise level to well above it, and thereby increased the coherence life time as compared with the beats produced by a transform-limited pulse. Closed-loop methods can thus effectively identify states that are robust against dephasing without any previous information about the system-environment interaction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Branderhorst, Matthijs P A -- Londero, Pablo -- Wasylczyk, Piotr -- Brif, Constantin -- Kosut, Robert L -- Rabitz, Herschel -- Walmsley, Ian A -- New York, N.Y. -- Science. 2008 May 2;320(5876):638-43. doi: 10.1126/science.1154576.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18451296" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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