Magnon-mediated qubit coupling determined via dissipation measurements

TL;DR

This paper experimentally measures the magnon-mediated coupling between NV centers in diamond, revealing how magnons influence spin interactions and aiding the development of hybrid quantum systems for quantum information processing.

Contribution

It provides the first experimental characterization of magnon-mediated NV-NV coupling via dissipation measurements, aligning with a dipolar interaction model.

Findings

Magnon-induced self-energy affects NV center coherence.

Experimental data matches dipolar coupling model.

Method enables characterization of hybrid quantum systems.

Abstract

Controlled interaction between localized and delocalized solid-state spin systems offers a compelling platform for on-chip quantum information processing with quantum spintronics. Hybrid quantum systems (HQSs) of localized nitrogen-vacancy (NV) centers in diamond and delocalized magnon modes in ferrimagnets-systems with naturally commensurate energies-have recently attracted significant attention, especially for interconnecting isolated spin qubits at length-scales far beyond those set by the dipolar coupling. However, despite extensive theoretical efforts, there is a lack of experimental characterization of the magnon-mediated interaction between NV centers, which is necessary to develop such hybrid quantum architectures. Here, we experimentally determine the magnon-mediated NV-NV coupling from the magnon-induced self-energy of NV centers. Our results are quantitatively consistent with a model in which the NV center is coupled to magnons by dipolar interactions. This work provides a versatile tool to characterize HQSs in the absence of strong coupling, informing future efforts to engineer entangled solid-state systems.