Thermal Excitation of Multi-Photon Dressed States in Circuit Quantum Electrodynamics

TL;DR

This paper investigates the interaction between a superconducting qubit and microwave photons, demonstrating the excitation of multi-photon dressed states and analyzing thermal effects in circuit QED.

Contribution

It provides experimental observation of up to three-photon dressed states in circuit QED and compares results with a generalized Jaynes-Cummings model.

Findings

Good quantitative agreement with the generalized Jaynes-Cummings model.

Thermal fields can be studied in detail using superconducting circuits.

Observation of multi-photon dressed states up to three photons.

Abstract

The exceptionally strong coupling realizable between superconducting qubits and photons stored in an on-chip microwave resonator allows for the detailed study of matter-light interactions in the realm of circuit quantum electrodynamics (QED). Here we investigate the resonant interaction between a single transmon-type multilevel artificial atom and weak thermal and coherent fields. We explore up to three photon dressed states of the coupled system in a linear response heterodyne transmission measurement. The results are in good quantitative agreement with a generalized Jaynes-Cummings model. Our data indicates that the role of thermal fields in resonant cavity QED can be studied in detail using superconducting circuits.