Multi-photon spectroscopy of a hybrid quantum system

TL;DR

This paper presents experimental multi-photon spectroscopy of a hybrid quantum system with a superconducting qubit and a defect, revealing strongly coupled hybridized states and comparing results with a comprehensive theoretical model.

Contribution

It demonstrates the first detailed experimental exploration of multi-photon processes in a strongly coupled hybrid quantum system with theoretical validation.

Findings

Excellent agreement between experiment and theory across various parameters

Observation of hybridized states in the strongly interacting regime

Identification of multi-photon processes and anharmonic effects

Abstract

We report on experimental multi-photon spectroscopy of a hybrid quantum system consisting of a superconducting phase qubit coherently coupled to an intrinsic two-level defect. We directly probe hybridized states of the combined qubit-defect system in the strongly interacting regime, where both the qubit-defect coupling and the driving cannot be considered as weak perturbations. This regime is described by a theoretical model which incorporates anharmonic corrections, multi-photon processes and decoherence. We present a detailed comparison between experiment and theory and find excellent agreement over a wide range of parameters.