Recovering quantum gates from few average gate fidelities

Understand

Characterising quantum processes is a key task in and constitutes a challenge for the development of quantum technologies, especially at the noisy intermediate scale of today's devices.

• One method for characterising processes is randomised benchmarking, which is robust against state preparation and measurement (SPAM) errors, and can be used to benchmark Clifford gates.
• A complementing approach asks for full tomographic knowledge.
• Compressed sensing techniques achieve full tomography of quantum channels essentially at optimal resource efficiency.