Breakdown of Fluctuational Electrodynamics in the Extreme Near Field

Philippe Ben-Abdallah

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arXiv · 2606.05845

Breakdown of Fluctuational Electrodynamics in the Extreme Near Field

Philippe Ben-Abdallah

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Abstract

Fluctuational electrodynamics relies on the assumption that thermal fluctuations in distinct bodies are statistically independent. It is shown that this approximation breaks down in the extreme near-field regime, where hybridization of surface phonon-polaritons across nanometric vacuum gaps generates finite fluctuating-current cross correlations between opposite interfaces. Using a microscopic coupled-oscillator model combined with a Green-tensor formulation of the Poynting vector, the resulting correlation-induced correction to radiative heat transfer is derived. For polar materials, these correlations become significant when the hybridization energy approaches the intrinsic damping rate and can substantially modify conventional fluctuational-electrodynamics predictions at subnanometric separations.

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Philippe Ben-Abdallah. 2026-06-04. Breakdown of Fluctuational Electrodynamics in the Extreme Near Field. https://arxiv.org/abs/2606.05845

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