Floquet spectroscopy of a strongly driven quantum dot charge qubit with a microwave resonator

TL;DR

This study explores the behavior of a strongly driven quantum dot charge qubit coupled to a microwave resonator, revealing quantum phenomena like multi-photon processes and interference patterns through Floquet spectroscopy.

Contribution

It provides experimental insights into Floquet states in a driven quantum dot qubit system and compares theoretical models with observed quantum features.

Findings

Observation of multi-photon processes

Detection of Landau-Zener-Stückelberg interference

Validation of Floquet theory in driven qubits

Abstract

We experimentally investigate a strongly driven GaAs double quantum dot charge qubit weakly coupled to a superconducting microwave resonator. The Floquet states emerging from strong driving are probed by tracing the qubit - resonator resonance condition. This way we probe the resonance of a qubit that is driven in an adiabatic, a non-adiabatic, or an intermediate rate showing distinct quantum features of multi-photon processes and Landau-Zener-St\"uckelberg interference pattern. Our resonant detection scheme enables the investigation of novel features when the drive frequency is comparable to the resonator frequency. Models based on adiabatic approximation, rotating wave approximation, and Floquet theory explain our experimental observations.