Beyond Spectroscopic Strong Coupling: Operational Benchmarks for Cavity-to-Magnon Quantum Transfer
Abstract
Normal-mode splitting reveals coherent cavity--magnon hybridization but does not certify finite-time quantum-state transfer. We describe quantum transfer in a passive, linear cavity--magnon system coupled to thermal reservoirs as a thermal-loss channel specified by its coherent transmissivity η and output-referred thermal population ν. For single-rail qubits, we calculate the phase-corrected average fidelity and compare it with the deterministic measure-and-prepare benchmark of 2/3. A Bell pair shared by the cavity and an isolated reference retains reference--magnon entanglement if and only if η>ν. An input squeezed vacuum of strength r yields sub-vacuum magnon fluctuations if and only if ν<η(1−e−2r)/2. When the initial magnon and both reservoirs have the same occupation, an analytically determined peak-transmissivity time optimizes all three tasks. These task-dependent benchmarks show that a conventional linewidth-based strong-coupling criterion does not guarantee quantum-transfer performance. Conversely, entanglement or squeezing can survive below that spectroscopic reference when the added noise is sufficiently low. These benchmarks provide quantitative targets for transfer timing and thermal-noise control in intracavity-to-magnon quantum interfaces.
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BibTeX
@misc{xinyi2026beyond,
title = {{Beyond Spectroscopic Strong Coupling: Operational Benchmarks for Cavity-to-Magnon Quantum Transfer}},
author = {Huang Xinyi and Zhang Xiang and Zhao Dongxing},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.09921},
eprint = {2610.09921},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.09921},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Beyond Spectroscopic Strong Coupling: Operational Benchmarks for Cavity-to-Magnon Quantum Transfer
AU - Huang Xinyi
AU - Zhang Xiang
AU - Zhao Dongxing
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2610.09921
UR - https://arxiv.org/abs/2610.09921
AB - Normal-mode splitting reveals coherent cavity--magnon hybridization but does not certify finite-time quantum-state transfer. We describe quantum transfer in a passive, linear cavity--magnon system coupled to thermal reservoirs as a thermal-loss channel specified by its coherent transmissivity η and output-referred thermal population ν. For single-rail qubits, we calculate the phase-corrected average fidelity and compare it with the deterministic measure-and-prepare benchmark of 2/3. A Bell pair shared by the cavity and an isolated reference retains reference--magnon entanglement if and only if η>ν. An input squeezed vacuum of strength r yields sub-vacuum magnon fluctuations if and only if ν<η(1−e^−2r)/2. When the initial magnon and both reservoirs have the same occupation, an analytically determined peak-transmissivity time optimizes all three tasks. These task-dependent benchmarks show that a conventional linewidth-based strong-coupling criterion does not guarantee quantum-transfer performance. Conversely, entanglement or squeezing can survive below that spectroscopic reference when the added noise is sufficiently low. These benchmarks provide quantitative targets for transfer timing and thermal-noise control in intracavity-to-magnon quantum interfaces.
ER -