High-fidelity gate operations for quantum computing beyond dephasing time limits

TL;DR

This paper demonstrates high-fidelity quantum gate operations exceeding 99.8% fidelity, surpassing environmental dephasing limits and threshold requirements for quantum error correction, by employing error-compensating and noise-decoupling techniques.

Contribution

It introduces robust quantum gate protocols that outperform traditional limits set by control precision and environmental noise, advancing reliable quantum computing.

Findings

Achieved average gate fidelities up to 99.8%.

Demonstrated gates surpassing environmental dephasing limits.

Validated robustness against control errors and environmental noise.

Abstract

The implementation of quantum gates with fidelities that exceed the threshold for reliable quantum computing requires robust gates whose performance is not limited by the precision of the available control fields. The performance of these gates also should not be affected by the noisy environment of the quantum register. Here we use randomized benchmarking of quantum gate operations to compare the performance of different families of gates that compensate errors in the control field amplitudes and decouple the system from the environmental noise. We obtain average fidelities of up to 99.8\%, which exceeds the threshold value for some quantum error correction schemes as well as the expected limit from the dephasing induced by the environment.