NbTiN Nanowire Resonators for Spin-Photon Coupling on Solid Neon

TL;DR

This paper demonstrates NbTiN nanowire resonators' high quality factors on solid neon, enabling strong charge and spin-photon coupling for scalable quantum computing, supported by experimental validation and theoretical analysis.

Contribution

It provides the first experimental validation of NbTiN nanowire resonators on solid neon and offers theoretical designs for spin-photon coupling strategies.

Findings

Resonators maintain high quality factors (~10^5) after neon deposition and electron loading.

Theoretical analysis shows potential for >99.99% single-qubit gate fidelity.

Designs enable strong spin-photon interactions in neon-based platforms.

Abstract

Electrons floating on a solid neon exhibit long charge coherence times, making them attractive for hybrid quantum systems. When combined with high-quality, high-impedance superconducting resonators and a local magnetic field gradient, this platform enables strong charge--photon and spin--charge coupling-key ingredients for scalable spin qubit architectures. In this work, we demonstrate that NbTiN nanowire resonators maintain high quality factors around 10^5 after depositing solid neon onto the resonators and subsequently loading electrons onto the neon surface, validating their suitability for electrons-on-neon platforms. Building on these experimental results, we theoretically analyze micromagnet designs and coupling strategies that can enable spin-photon interactions in this platform. Our analysis outlines performance targets for next-generation devices, showing that, at the charge sweet spot, spin qubit gate fidelities exceeding 99.99% for single-qubit operations and 99.9% for two-qubit operations are achievable with natural neon.