# Optimal Clock Speed of Single-Qubit Operations on Open Quantum Systems

## TL;DR

This paper demonstrates that the fidelity of single-qubit gates in open quantum systems peaks at an optimal drive amplitude, indicating a maximum clock speed for quantum operations due to drive-induced decoherence.

## Contribution

It introduces a method to determine the optimal drive amplitude for maximum fidelity in single-qubit gates on open quantum systems, considering drive-induced decoherence.

## Key findings

- Fidelity peaks at a specific drive amplitude.
- Fidelity depends on drive-induced and relaxation dissipation.
- Optimal clock speed exists for single-qubit operations.

## Abstract

Efficient implementation of quantum algorithms requires single- or multi-qubit gates with high fidelity. In this report, we report that the fidelity of single-qubit gate operations on open quantum systems has a maximum value corresponding to an optimum value of the drive-amplitude in the presence of drive-induced decoherence. To show this, we use a previously reported fluctuation-regulated quantum master equation [Phys. Rev. A 97, 063837 (2018)]. The fidelity is found to be a function of the drive-induced dissipative terms as well as the relaxation terms arising from the qubit-environment coupling; as a result, it behaves non-monotonically with the drive-amplitude. The existence of an optimum drive-amplitude implies that the single-qubit operations on open quantum systems would have an optimal clock speed.