Enhancement of quantum speed limit time due to cooperative effects in multilevel systems

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.

6 pages, 4 figures. Minor revisions and updated journal reference

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Cited by in corpus (7)

• Quantum speed limits: from Heisenberg's uncertainty principle to optimal quantum control
• Geometric quantum speed limits and short-time accessibility to unitary operations
• Quantum speed limit for robust state characterization and engineering
• Taming quantum systems: A tutorial for using shortcuts-to-adiabaticity, quantum optimal control, and reinforcement learning
• Optimal control of many-body quantum dynamics: chaos and complexity
• Analysis of lower bounds for quantum control times and their relation to the quantum speed limit
• Time-optimal control fields for quantum systems with multiple avoided crossings