Matchgate benchmarking: Scalable benchmarking of a continuous family of many-qubit gates

We propose a method to reliably and efficiently extract the fidelity of many-qubit quantum circuits composed continuously parametrized two-qubit gates.
This method, which we call matchgate benchmarking, relies on advanced techniques from randomized benchmarking as well as insights from of the representation theory of matchgate circuits.
We argue the formal correctness and scalability of the protocol, and moreover demonstrate its functionality in practice on the publicly available Rigetti Aspen-8 quantum computer.