  We introduce ACES, a method for scalable noise metrology of quantum circuits
that stands for Averaged Circuit Eigenvalue Sampling. It simultaneously
estimates the individual error rates of all the gates in collections of quantum
circuits, and can even account for space and time correlations between these
gates. ACES strictly generalizes randomized benchmarking (RB), interleaved RB,
simultaneous RB, and several other related techniques. However, ACES provides
much more information and provably works under strictly weaker assumptions than
these techniques. Finally, ACES is extremely scalable: we demonstrate with
numerical simulations that it simultaneously and precisely estimates all the
Pauli error rates on every gate and measurement in a 100 qubit quantum device
using fewer than 20 relatively shallow Clifford circuits and an experimentally
feasible number of samples. By learning the detailed gate errors for large
quantum devices, ACES opens new possibilities for error mitigation, bespoke
quantum error correcting codes and decoders, customized compilers, and more.
