Parallel selective nuclear spin addressing for fast high-fidelity quantum gates

TL;DR

This paper introduces a novel method for fast, high-fidelity quantum gates by selectively addressing nuclear spins through generalized electron spin control sequences, significantly reducing gate times in quantum systems like NV centers.

Contribution

The authors develop a new approach for simultaneous control of multiple nuclear spins, improving entangling gate efficiency and speed compared to traditional electron-nuclear gate sequences.

Findings

Reduces gate time by over 50% when limited by off-resonant coupling.

Achieves up to 22% faster gates when limited by electron-nuclear coupling.

Demonstrates potential applications in quantum information processing with NV centers.

Abstract

Due to their long coherence times, nuclear spins have gained considerable attention as physical qubits. Two-qubit gates between nuclear spins of distinct resonance frequencies can be mediated by electron spins, usually employing a sequence of electron-nuclear gates. Here we present a different approach inspired by, but not limited to, NV centers in diamond and discuss possible applications. To this end we generalize external electron spin control sequences for nuclear spin initialization and hyperpolarization to achieve the simultaneous control of distinct nuclear spins via an electron spin. This approach results in efficient entangling gates that, compared to standard techniques, reduce the gate time by more than 50% when the gate time is limited by off-resonant coupling to other spins, and by up to 22% when the gate time is limited by small electron-nuclear coupling.