Controllability of the coupled spin-half harmonic oscillator system

TL;DR

This paper analyzes the controllability of a quantum system combining a two-level atom and a harmonic oscillator, demonstrating that two resonant frequencies suffice to generate any unitary operation, advancing quantum control techniques.

Contribution

It provides a control-theoretic proof that minimal external fields can achieve complete controllability of the coupled quantum system.

Findings

Any unitary operator can be generated with two resonant frequencies.

The system is fully controllable using simple external controls.

The approach simplifies quantum control protocols for coupled systems.

Abstract

We present a control-theoretic analysis of the system consisting of a two-level atom coupled with a quantum harmonic oscillator. We show that by applying external fields with just two resonant frequencies, any desired unitary operator can be generated.