Enhancement of quantum speed limit time due to cooperative effects in multilevel systems. (11th August 2015)

• Record Type: Journal Article
• Authors: Poggi, P M; Lombardo, F C; Wisniacki, D A
• Is Part Of: Journal of physics. Volume 48:Number 35(2015)
• Publication Date: 2015-08-11
• Subjects: quantum mechanics -- optimal quantum control -- quantum speed limit -- quantum state transfer -- avoided level crossings; 1315 -- 9440 T; Mathematical physics -- Periodicals; Statistical physics -- Periodicals; Quantum theory -- Periodicals; Matter -- Properties -- Periodicals; 530.105
• DOI: 10.1088/1751-8113/48/35/35FT02
• Languages: English
• ISSNs: 1751-8113

Abstract

Abstract: Deriving minimum evolution times is of paramount importance in quantum mechanics. Bounds on the speed of evolution are given by the so called quantum speed limit (QSL). In this work we use quantum optimal control methods to study the QSL for driven many level systems which exhibit local two-level interactions in the form of avoided crossings (ACs). Remarkably, we find that optimal evolution times are proportionally smaller than those predicted by the well-known two-level case, even when the ACs are isolated. We show that the physical mechanism for such enhancement is due to non-trivial cooperative effects between the AC and other levels, which are dynamically induced by the shape of the optimized control field.