Résumé |
Superconducting circuits are seen as a promising platform for engineering complex
quantum states, either with the purpose of implementing large scale quantum
algorithms, or to emulate quantum many-body problems of interest for physicists.
We investigate both experimentally and theoretically the possibility
to realize quantum impurity models that provide not only bosonic
analogs to the electronic Kondo effect, but also strong coupling regimes
of quantum electrodynamics, equivalent to boosting the fine structure
constant close to unity.
As a result, we evidence several interaction-driven effects that represent
two sides of the same coin: i) a giant renormalization of the frequency of
an artificial atom (the impurity) by vacuum fluctuations of the quantum field;
ii) a broadband inelastic scattering of the external photons by the internal
dynamics of the atom.
We discuss also critically the advantages and limitations of superconducting
circuits for the exploration of many-body phenomena. |