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arXiv · 2110.14050

First-principles calculations of phonon transport across a vacuum gap

Takuro Tokunaga·Masao Arai·Kazuaki Kobayashi·Wataru Hayami·Shigeru Suehara·Takuma Shiga·Keunhan Park·Mathieu Francoeur
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Abstract

Phonon transport across a vacuum gap separating intrinsic silicon crystals is predicted via the atomistic Green's function method combined with first-principles calculations of all interatomic force constants. The overlap of electron wave functions in the vacuum gap generates weak covalent interaction between the silicon surfaces, thus creating a pathway for phonons. Phonon transport, dominated by acoustic modes, exceeds near-field radiation for vacuum gaps smaller than ~ 1 nm. The first-principles-based approach proposed in this work is critical to accurately quantify the contribution of phonon transport to heat transfer in the extreme near field.

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Takuro Tokunaga, Masao Arai, Kazuaki Kobayashi, Wataru Hayami, Shigeru Suehara, Takuma Shiga, Keunhan Park, Mathieu Francoeur. 2021-10-26. First-principles calculations of phonon transport across a vacuum gap. https://doi.org/10.1103/physrevb.105.045410

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