Experimental implementation of non-Clifford interleaved randomized benchmarking with a controlled-S gate

Abstract

Hardware-efficient transpilation of quantum circuits to a quantum device native gate set is essential for the execution of quantum algorithms on noisy quantum computers. Typical quantum devices utilize a gate set with a single two-qubit Clifford entangling gate per pair of coupled qubits; however, in some applications access to a non-Clifford two-qubit gate can result in more optimal circuit decompositions and also allows more flexibility in optimizing over noise. We demonstrate calibration of a low-error non-Clifford controlled-π/2 phase (CS) gate on a cloud-based IBM Quantum system using the Qiskit Pulse framework. To measure the gate error of the calibrated cs gate we perform non-Clifford cnot-dihedral interleaved randomized benchmarking. We are able to obtain a gate error of 5.9(7)×10^(−3) at a gate length 263 ns, which is close to the coherence limit of the associated qubits, and lower error than the back-end standard calibrated CNOT gate.