Searching for quantum optimal controls under severe constraints

Gregory Riviello, Katharine Moore Tibbetts, Constantin Brif, Ruixing Long, Re Bing Wu, Tak San Ho, Herschel Rabitz

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

The success of quantum optimal control for both experimental and theoretical objectives is connected to the topology of the corresponding control landscapes, which are free from local traps if three conditions are met: (1) the quantum system is controllable, (2) the Jacobian of the map from the control field to the evolution operator is of full rank, and (3) there are no constraints on the control field. This paper investigates how the violation of assumption (3) affects gradient searches for globally optimal control fields. The satisfaction of assumptions (1) and (2) ensures that the control landscape lacks fundamental traps, but certain control constraints can still introduce artificial traps. Proper management of these constraints is an issue of great practical importance for numerical simulations as well as optimization in the laboratory. Using optimal control simulations, we show that constraints on quantities such as the number of control variables, the control duration, and the field strength are potentially severe enough to prevent successful optimization of the objective. For each such constraint, we show that exceeding quantifiable limits can prevent gradient searches from reaching a globally optimal solution. These results demonstrate that careful choice of relevant control parameters helps to eliminate artificial traps and facilitates successful optimization.

Original languageEnglish (US)
Article number043401
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Volume91
Issue number4
DOIs
StatePublished - Apr 6 2015

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Searching for quantum optimal controls under severe constraints'. Together they form a unique fingerprint.

  • Cite this