Improved Electron-Nuclear Quantum Gates for Spin Sensing and Control

TL;DR

This paper introduces a generalized DDRF framework for electron-nuclear spin gates, enhancing sensitivity and control in quantum sensing applications through analytical modeling and experimental validation.

Contribution

It develops a comprehensive DDRF model that improves gate design, sensitivity, and control for spin sensing, supported by experiments and numerical analysis.

Findings

60x sensitivity enhancement for weakly coupled spins

Analytical model explains gate selectivity and Rabi frequencies

Optimized quantum gates for multi-qubit registers

Abstract

The ability to sense and control nuclear spins near solid-state defects might enable a range of quantum technologies. Dynamically Decoupled Radio-Frequency (DDRF) control offers a high degree of design flexibility and long electron-spin coherence times. However, previous studies considered simplified models and little is known about optimal gate design and fundamental limits. Here, we develop a generalised DDRF framework that has important implications for spin sensing and control. Our analytical model, which we corroborate by experiments on a single NV center in diamond, reveals the mechanisms that govern the selectivity of gates and their effective Rabi frequencies, and enables flexible detuned gate designs. We apply these insights to numerically show a 60x sensitivity enhancement for detecting weakly coupled spins and study the optimisation of quantum gates in multi-qubit registers. These results advance the understanding for a broad class of gates and provide a toolbox for application-specific design, enabling improved quantum control and sensing.