Mirror Randomized Benchmarking (MRB)

Motivations

• Finding a scalable protocol which do not require heavy classical processing to evaluate the output of the quantum circuit

Protocol

• The initial state \(\rho_0\) is prepared with a random layer of single-qubit Clifford gate (24 possible gates). This layer is inversed at the end of the circuit.
• An \(l\)-depth circuit contains \(l/2\) layers of \(\mu\)-distributed random gates \(G_1, G_2, ... G_{l/2}\) and \(l/2\) layers of the reversed gates.
• The layers of random gates are interleaved with random Pauli gates that are used to twirl the noise (yellow boxes).
• The figure of merit for success is computed from the hamming distance between the sampled and success bitstring.

Limitations

• If the errors of \(\mu\)-distributed gates and their inverse are correlated, MRB slightly underestimates the error rate of the gate set.

References