Circuit quantum electrodynamics architecture for gate-defined quantum dots in silicon

We demonstrate a hybrid device architecture where the charge states in a double quantum dot (DQD) formed in a Si/SiGe heterostructure are read out using an on-chip superconducting microwave cavity. A quality factor Q1⁄4 5400 is achieved by selectively etching away regions of the quantum well and by reducing photon losses through low-pass filtering of the gate bias lines. Homodyne measurements of the cavity transmission reveal DQD charge stability diagrams and a charge-cavity coupling rate gc=2p 1⁄4 23 MHz. These measurements indicate that electrons trapped in a Si DQD can be effectively coupled to microwave photons, potentially enabling coherent electron-photon interactions in silicon. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4974536]