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arXiv · 2609.36270

Fundamental concepts of thermal phonon coherence

Theodore Maranets·Haoran Cui·Milad Nasiri·Evan Doe·Yan Wang
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Abstract

As scientists seek to transcend traditional material property relationships, novel structures with artificial periodicity, configurational complexity, and disorder are increasingly being explored. For phonons, these architectures can induce significant phase correlations, which strongly shifts lattice heat conduction away from the conventional framework of particle-like scattering. This thermal phonon coherence can develop in space and time separately, resulting in distinct wave-like phenomena. Here we rigorously outline the theories of phonon spatial and temporal coherence. Crucially, this review focuses on demystifying and building conceptual understanding of the fundamental principles linking the various thermal conductivity and phonon property results reported in the literature. Furthermore, we use this understanding to establish a comprehensive physical picture of the wave nature of thermal phonons, unifying the spatial and temporal coherence theories. Altogether, the theoretical dissections in this review provide an extensive knowledge base for understanding and engineering thermal phonons in complex materials.

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Theodore Maranets, Haoran Cui, Milad Nasiri, Evan Doe, Yan Wang. 2026-09-28. Fundamental concepts of thermal phonon coherence. https://arxiv.org/abs/2609.36270

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