Print Email Facebook Twitter Broken selection rule in the quantum Rabi model Title Broken selection rule in the quantum Rabi model Author Forn Diaz, P. (TU Delft QN/Quantum Transport; University of Waterloo; Kavli institute of nanoscience Delft) Romero, G. (Universidad de Santiago de Chile) Harmans, C.J.P.M. (TU Delft QN/Quantum Transport; Kavli institute of nanoscience Delft) Solano, E. (Basque Foundation for Science; University of the Basque Country) Mooij, J.E. (TU Delft QN/Quantum Transport; Kavli institute of nanoscience Delft) Date 2016-06-07 Abstract Understanding the interaction between light and matter is very relevant for fundamental studies of quantum electrodynamics and for the development of quantum technologies. The quantum Rabi model captures the physics of a single atom interacting with a single photon at all regimes of coupling strength. We report the spectroscopic observation of a resonant transition that breaks a selection rule in the quantum Rabi model, implemented using an LC resonator and an artificial atom, a superconducting qubit. The eigenstates of the system consist of a superposition of bare qubit-resonator states with a relative sign. When the qubit-resonator coupling strength is negligible compared to their own frequencies, the matrix element between excited eigenstates of different sign is very small in presence of a resonator drive, establishing a sign-preserving selection rule. Here, our qubit-resonator system operates in the ultrastrong coupling regime, where the coupling strength is 10% of the resonator frequency, allowing sign-changing transitions to be activated and, therefore, detected. This work shows that sign-changing transitions are an unambiguous, distinctive signature of systems operating in the ultrastrong coupling regime of the quantum Rabi model. These results pave the way to further studies of sign-preserving selection rules in multiqubit and multiphoton models. Subject Quantum opticsQubitsSuperconducting devices To reference this document use: http://resolver.tudelft.nl/uuid:ed0ca028-6997-4424-b4cb-06a309baa855 DOI https://doi.org/10.1038/srep26720 ISSN 2045-2322 Source Scientific Reports, 6 Part of collection Institutional Repository Document type journal article Rights © 2016 P. Forn Diaz, G. Romero, C.J.P.M. Harmans, E. Solano, J.E. Mooij Files PDF srep26720.pdf 2.15 MB Close viewer /islandora/object/uuid:ed0ca028-6997-4424-b4cb-06a309baa855/datastream/OBJ/view