Indirect control of quantum system via accessor: pure coherent control without system excitation

TL;DR

This paper explores a novel method for controlling quantum systems indirectly through a quantum accessor without external classical fields on the system, offering advantages like fewer qubits and independence from energy-level structures.

Contribution

It introduces a pure coherent control scheme that does not require system excitation, expanding control options for finite-dimensional quantum systems.

Findings

Achieves complete controllability for 2 and 3 dimensional systems.

Uses fewer qubits in the accessor compared to traditional methods.

Does not depend on the energy-level structure of the controlled system.

Abstract

A pure indirect control of quantum systems via quantum accessor is investigated. In this control scheme, we do not apply any external classical excitation fields on the controlled system and we control a quantum system via a quantum accessor and classical control fields control the accessor only. Complete controllability is investigated for arbitrary finite dimensional quantum systems and exemplified by 2 and 3 dimensional systems. The scheme exhibits some advantages; it uses less qubits in accessor and does not depend on the energy-level structure of the controlled system.