Split-gate cavity coupler for silicon circuit quantum electrodynamics
Felix Borjans, Xanthe Croot, Stefan Putz, Xiao Mi, Samuel Quinn, Andrew Pan, Joseph Kerckhoff, Emily Pritchett, Clayton A. C. Jackson, L. F. Edge, Richard S. Ross, Thaddeus D. Ladd, Matthew Borselli, Mark F. Gyure, J. R. Petta · Applied Physics Letters · 2020
Coherent charge-photon and spin-photon coupling has recently been achieved in silicon double quantum dots (DQDs). Here, we demonstrate a versatile split-gate cavity-coupler that allows more than one DQD to be coupled to the same microwave cavity. Measurements of the cavity transmission as a function of level detuning yield a charge cavity coupling rate of gc/2π= 58 MHz, a charge decoherence rate of γc/2π= 36 MHz, and a cavity decay rate of κ/2π= 1.2 MHz. The charge cavity coupling rate is in good agreement with device simulations. Our coupling technique can be extended to enable simultaneous coupling of multiple DQDs to the same cavity mode, opening the door to long-range coupling of semiconductor qubits using microwave frequency photons.