# High-fidelity single-qubit gates in a strongly driven quantum dot hybrid qubit with $1/f$ charge noise

## TL;DR

This paper demonstrates that strong microwave driving combined with pulse shaping and simultaneous detuning and tunneling modulation can significantly improve the fidelity of single-qubit gates in semiconductor hybrid qubits affected by charge noise.

## Contribution

The study introduces a theoretical and numerical analysis showing how pulse shaping and AC sweet spots enhance gate fidelity in the presence of charge and phonon noise.

## Key findings

- Achievable $X_{}$ gate fidelities exceed 99.9%.
- Pulse shaping suppresses strong-driving effects.
- AC sweet spots mitigate charge noise impact.

## Abstract

Semiconductor double quantum dot hybrid qubits are promising candidates for high-fidelity quantum computing. However, their performance is limited by charge noise, which is ubiquitous in solid-state devices, and phonon-induced dephasing. Here we explore methods for improving the quantum operations of a hybrid qubit, using strong microwave driving to enable gate operations that are much faster than decoherence processes. Using numerical simulations and a theoretical method based on a cumulant expansion, we analyze qubit dynamics in the presence of $1/f$ charge noise, which forms the dominant decoherence mechanism in many solid-state devices. We show that, while strong-driving effects and charge noise both reduce the quantum gate fidelity, simple pulse-shaping techniques effectively suppress the strong-driving effects. Moreover, a broad AC sweet spot emerges when the detuning parameter and the tunneling coupling are driven simultaneously. Taking into account phonon-mediated noise, we find that it should be possible to achieve $X_{\pi}$ gates with fidelities higher than $99.9\%$.