Experimental Monte Carlo Quantum Process Certification

TL;DR

This paper demonstrates an experimental implementation of Monte Carlo quantum process certification, providing a practical method to assess quantum gate fidelity without full process tomography, suitable for multi-qubit systems.

Contribution

It introduces an experimental approach to Monte Carlo quantum process certification, enabling efficient fidelity estimation for multi-qubit gates in circuit QED systems.

Findings

Successfully certified two-qubit gates like cphase and cnot

Extended the method to three-qubit gates such as Toffoli

Reduced complexity compared to traditional quantum process tomography

Abstract

Experimental implementations of quantum information processing have now reached a level of sophistication where quantum process tomography is impractical. The number of experimental settings as well as the computational cost of the data post-processing now translates to days of effort to characterize even experiments with as few as 8 qubits. Recently a more practical approach to determine the fidelity of an experimental quantum process has been proposed, where the experimental data is compared directly to an ideal process using Monte Carlo sampling. Here we present an experimental implementation of this scheme in a circuit quantum electrodynamics setup to determine the fidelity of two qubit gates, such as the cphase and the cnot gate, and three qubit gates, such as the Toffoli gate and two sequential cphase gates.