Controlling chaos in the quantum regime using adaptive measurements

TL;DR

This paper introduces a quantum feedback control method using adaptive measurements to regulate chaos in a quantum Duffing oscillator, highlighting the role of measurement backaction in quantum chaos control.

Contribution

It presents a novel quantum control scheme based solely on measurement backaction, enabling control of chaos in a quantum system near the quantum-classical boundary.

Findings

Adaptive measurement techniques can suppress or induce chaos.

Quantum Lyapunov exponent quantifies control effectiveness.

Control extends the quantum regime where chaos can be managed.

Abstract

The continuous monitoring of a quantum system strongly influences the emergence of chaotic dynamics near the transition from the quantum regime to the classical regime. Here we present a feedback control scheme that uses adaptive measurement techniques to control the degree of chaos in the driven-damped quantum Duffing oscillator. This control relies purely on the measurement backaction on the system, making it a uniquely quantum control, and is only possible due to the sensitivity of chaos to measurement. We quantify the effectiveness of our control by numerically computing the quantum Lyapunov exponent over a wide range of parameters. We demonstrate that adaptive measurement techniques can control the onset of chaos in the system, pushing the quantum-classical boundary further into the quantum regime.