Resonance at the Rabi frequency in a superconducting flux qubit

TL;DR

This paper investigates resonance phenomena at the Rabi frequency in a superconducting flux qubit coupled to a resonator, demonstrating potential for quantum amplification and attenuation through doubly dressed states.

Contribution

It introduces a theoretical framework for understanding Rabi frequency resonance in flux qubits driven by dual signals, highlighting applications in quantum amplification and attenuation.

Findings

Resonance at the Rabi frequency enables signal amplification and attenuation.

Doubly dressed states facilitate control over qubit-resonator interactions.

Potential use as a quantum microwave laser or attenuator.

Abstract

We analyze a system composed of a superconducting flux qubit coupled to a transmission-line resonator driven by two signals with frequencies close to the resonator's harmonics. The first strong signal is used for exciting the system to a high energetic state while a second weak signal is applied for probing effective eigenstates of the system. In the framework of doubly dressed states we showed the possibility of amplification and attenuation of the probe signal by direct transitions at the Rabi frequency. We present a brief review of theoretical and experimental works where a direct resonance at Rabi frequency have been investigated in superconducting flux qubits. The interaction of the qubit with photons of two harmonics has prospects to be used as a quantum amplifier (microwave laser) or an attenuator.