Optimally Driven Dressed Qubits

TL;DR

This paper introduces a novel dressed-qubit control protocol that eliminates counter-rotating terms, surpassing traditional methods by enhancing gate speed, fidelity, and coherence without relying on the rotating-wave approximation.

Contribution

The authors develop a dressed-qubit control scheme that removes the counter-rotating term using a single coupling axis, improving performance metrics and simplifying implementation.

Findings

Eliminates the need for the rotating-wave approximation.

Improves single-qubit gate speed and two-qubit gate fidelity.

Enhances spectroscopic range, clock stability, and coherence preservation.

Abstract

The applicability and performance of qubits dressed by classical fields are limited because their control protocols give rise to an undesired counter-rotating term (CRT). This in turn forces operation in a regime where a (dressed) rotating-wave approximation (RWA) is valid, thereby restricting key aspects of their operation. Here, using only a single coupling axis in the laboratory frame, we introduce a dressed-qubit control protocol that optimally removes the CRT, eliminating the need for the RWA and delivering substantial improvements in multiple performance metrics, including single-qubit gate speed, two-qubit gate fidelity, spectroscopic range, clock stability, and coherence preservation. In addition, we provide a general parameterization together with a Floquet-based coherence-time expression, which elucidates the protocol's working principles and lowers the barrier to adoption. Collectively, these advances position our scheme as the state-of-the-art strategy for qubit control, paving the way for a wider class of quantum technologies to be realized using dressed-qubit architectures.