Non-exponential Fidelity Decay in Randomized Benchmarking with Low-Frequency Noise

TL;DR

This paper demonstrates that non-exponential fidelity decay in randomized benchmarking of quantum dot qubits can be explained by low-frequency noise, leading to improved fidelity estimates and advancing silicon-based quantum computing.

Contribution

It extends randomized benchmarking analysis to account for low-frequency noise, revealing multiple exponential decay rates and more accurate fidelity assessments.

Findings

Non-exponential decay explained by low-frequency noise models

Achieved up to 99.9% fidelity in silicon quantum dots

Enhanced qubit characterization methods for fault-tolerant quantum computing

Abstract

We show that non-exponential fidelity decays in randomized benchmarking experiments on quantum dot qubits are consistent with numerical simulations that incorporate low-frequency noise. By expanding standard randomized benchmarking analysis to this experimental regime, we find that such non-exponential decays are better modeled by multiple exponential decay rates, leading to an instantaneous control fidelity for isotopically-purified-silicon MOS quantum dot qubits which can be as high as 99.9% when low-frequency noise conditions and system calibrations are favorable. These advances in qubit characterization and validation methods underpin the considerable prospects for silicon as a qubit platform for fault-tolerant quantum computation.