Quantum Control in Open and Periodically Driven Systems

TL;DR

This paper reviews how quantum control techniques, especially Floquet engineering, utilize bound states in open and periodically driven systems to suppress decoherence and create new topological phases, advancing quantum technology.

Contribution

It provides a comprehensive review of recent progress in controlling decoherence and synthesizing topological phases through bound states in open and driven quantum systems.

Findings

Bound states can suppress decoherence in quantum systems.

Periodic driving enables control over bound states and topological phases.

Floquet engineering is a versatile tool for quantum control.

Abstract

Quantum technology resorts to efficient utilization of quantum resources to realize technique innovation. The systems are controlled such that their states follow the desired manners to realize different quantum protocols. However, the decoherence caused by the system-environment interactions causes the states deviating from the desired manners. How to protect quantum resources under the coexistence of active control and passive decoherence is of significance. Recent studies have revealed that the decoherence is determined by the feature of the system-environment energy spectrum: Accompanying the formation of bound states in the energy spectrum, the decoherence can be suppressed. It supplies a guideline to control decoherence. Such idea can be generalized to systems under periodic driving. By virtue of manipulating Floquet bound states in the quasienergy spectrum, coherent control via periodic driving dubbed as Floquet engineering has become a versatile tool not only in controlling decoherence, but also in artificially synthesizing exotic topological phases. We will review the progress on quantum control in open and periodically driven systems. Special attention will be paid to the distinguished role played by the bound states and their controllability via periodic driving in suppressing decoherence and generating novel topological phases.