Signal amplification in a qubit-resonator system

TL;DR

This paper investigates how a driven qubit-resonator system can amplify or attenuate a weak probe signal by analyzing the interaction of the qubit with high-amplitude driving and a secondary probing signal, providing insights into optimal conditions.

Contribution

It introduces a detailed analysis of signal amplification in a qubit-resonator system using dressed states and calculates transmission amplitudes under various parameters.

Findings

Regions of signal amplification and attenuation identified

Transmission amplitude depends on qubit energy and driving frequency detuning

Optimal parameters for amplification and attenuation discussed

Abstract

We study the dynamics of a qubit-resonator system, when the resonator is driven by two signals. The interaction of the qubit with the high-amplitude driving we consider in terms of the qubit dressed states. Interaction of the dressed qubit with the second probing signal can essentially change the amplitude of this signal. We calculate the transmission amplitude of the probe signal through the resonator as a function of the qubit's energy and the driving frequency detuning. The regions of increase and attenuation of the transmitted signal are calculated and demonstrated graphically. We present the influence of the signal parameters on the value of the amplification, and discuss the values of the qubit-resonator system parameters for an optimal amplification and attenuation of the weak probe signal.