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arXiv · 2510.26129

Quantum-coherent nonlinear interferometry using electron-phonon systems for entanglement-assisted terahertz sensing

Junya Ogiri·Hiroaki Minamide·Kunio Ishida
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Abstract

We present a theoretical framework for quantum-coherent nonlinear interferometry in which the nonlinear medium is modeled as active electron-phonon quantum systems rather than a passive $\chi^{(2)}$ converter. By explicitly retaining the quantum coherence of the coupled electron-phonon-photon dynamics, our model describes a two-stage buildup of entanglement - first between signal and idler photons and subsequently between idler photons mediated by material coherence. This coherent light-matter interaction imprints the internal dynamics of the medium onto the interferometer output, yielding phase-sensitive interference that enables indirect readout of terahertz-band signal modes via near-infrared detection. The results reveal a route toward entanglement-assisted terahertz sensing and establish a general framework for treating nonlinear quantum media as active components in interferometric architectures.

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Junya Ogiri, Hiroaki Minamide, Kunio Ishida. 2025-10-30. Quantum-coherent nonlinear interferometry using electron-phonon systems for entanglement-assisted terahertz sensing. https://arxiv.org/abs/2510.26129

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