Stockklauser, A.Scarlino, PasqualeKoski, J. V.Gasparinetti, S.Andersen, C. K.Reichl, C.Wegscheider, W.Ihn, T.Ensslin, K.Wallraff, A.2021-03-262021-03-262021-03-262017-03-0910.1103/PhysRevX.7.011030https://infoscience.epfl.ch/handle/20.500.14299/176125The strong coupling limit of cavity quantum electrodynamics (QED) implies the capability of a matterlike quantum system to coherently transform an individual excitation into a single photon within a resonant structure. This not only enables essential processes required for quantum information processing but also allows for fundamental studies of matter-light interaction. In this work, we demonstrate strong coupling between the charge degree of freedom in a gate-defined GaAs double quantum dot (DQD) and a frequency-tunable high impedance resonator realized using an array of superconducting quantum interference devices. In the resonant regime, we resolve the vacuum Rabi mode splitting of size 2g/2π=238 MHz at a resonator linewidth κ/2π=12 MHz and a DQD charge qubit decoherence rate of γ2/2π=40 MHz extracted independently from microwave spectroscopy in the dispersive regime. Our measurements indicate a viable path towards using circuit-based cavity QED for quantum information processing in semiconductor nanostructures.text::journal::journal article::research article