Native three-body interaction in superconducting circuits

This paper shows how a superconducting circuit can implement three qubits interacting via a direct three-body coupling. As the coupling is direct, the timescale of the interaction is extremely fast, on the order of a nanosecond. This coupling can be used to implement a controlled operation relevant for quantum computing, where the control is a quantum degree of freedom, and the operation time is so short that noise becomes much less relevant. The approach is general and could be used to implement other direct multi-qubit interactions in superconducting circuits.