One decade of quantum optimal control in the chopped random basis

TL;DR

This paper reviews a decade of development of the CRAB quantum optimal control method, highlighting its theoretical foundations, versatility, and applications across various quantum technologies and platforms.

Contribution

It provides a comprehensive overview of the CRAB algorithm's evolution, theoretical basis, and diverse applications in quantum control and technology.

Findings

CRAB effectively handles experimental constraints.

It enables switching from open-loop to closed-loop control.

The method has broad applicability across quantum platforms.

Abstract

The Chopped RAndom Basis (CRAB) ansatz for quantum optimal control has been proven to be a versatile tool to enable quantum technology applications, quantum computing, quantum simulation, quantum sensing, and quantum communication. Its capability to encompass experimental constraints -- while maintaining an access to the usually trap-free control landscape -- and to switch from open-loop to closed-loop optimization (including with remote access -- or RedCRAB) is contributing to the development of quantum technology on many different physical platforms. In this review article we present the development, the theoretical basis and the toolbox for this optimization algorithm, as well as an overview of the broad range of different theoretical and experimental applications that exploit this powerful technique.