Breakdown of Fluctuational Electrodynamics in the Extreme Near Field (opens in new tab)

Fluctuational electrodynamics relies on the assumption that thermal fluctuations in distinct bodies are statistically independent. We show that this approximation breaks down in the extreme near-field regime, where overlapping evanescent surface fields hybridize optical phonons across nanometric vacuum gaps and generate fluctuating-current cross correlations between opposite interfaces. Using a microscopic coupled-oscillator model combined with ...