Toward cQED with microchannel confined electrons on helium

Electrons floating above the surface of superfluid helium (eHe) are a paradigm for investigating the fundamental properties of low-dimensional electron systems and are emerging as a novel hybrid systems platform for quantum information science. Here we present hybrid system architectures, integrating microwave frequency devices with eHe microchannel control devices. Subjecting the electron system in the microchannel to microwave frequency excitation results in the generation of two-dimensional plasma oscillations along the length of the channel, which we find to have a lifetime of several nanoseconds. We find that the frequency of these plasmons can be tuned over a broad range of frequency (several GHz) by varying the areal density of electrons in the channel. Finally, we present device architectures that directly integrate standard superconducting resonators and superconducting qubits with microchannel control devices and discuss how these can be used to realize novel hybrid circuit quantum electrodynamic (cQED) systems.