Parametric multi-qubit architectures for superconducting quantum circuits

Parametric interactions provide a fast and selective way to couple qubits and superconducting resonators. These interactions, activated by modulating a tunable element at a linear combination of the qubit and resonator (or other qubit) frequencies, facilitate strong coupling between resonant modes that are far detuned in frequency, thus delivering a flexible and robust approach. Furthermore, the tunable coupler needs to provide high coupling rate and on-off ratio, to suppress unwanted parasitic interactions when idle. A modular design, suitable to couple qubits to each other and to resonators and waveguides, is desirable to enable both unitary [1] and dissipative [2] operations as well as long-range interconnects.

In this talk we describe dual and multi-qubit parametric circuit architectures. By connecting multiple qubits to a common resonator and injecting suitable parametric pumps, we can engineer fast dissipative stabilization of entanglement without speed-fidelity trade off [2]. While a single coupler provides a flexible platform to couple multiple elements with reduced wiring count, dual-transmon couplers provide intrinsic ZZ cancellation and greater modularity. We will discuss both approaches and present our latest experimental data.