2024/08/31 by Haoran Cui, Cui, Haoran, Theodore Maranets +5
Engineering · #FOS: Physical sciences #Heat Transfer and Boiling Studies #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Metallurgical Processes and Thermodynamics #Radiative Heat Transfer Studies
paper · pdf · doi:10.48550/arxiv.2409.00312
openalex publication_date 2024/08/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In nonmetallic crystals, heat is transported by phonons of different frequencies, each contributing differently to the overall heat flux spectrum. In this study, we demonstrate a significant redistribution of heat flux among phonon frequencies when phonons transmit across the interface between dissimilar solids. This redistribution arises from the natural tendency of phononic heat to re-establish the equilibrium distribution characteristic of the material through which it propagates. Remarkably, while the heat flux spectra of dissimilar solids are typically distinct in their bulk forms, they can become nearly identical in superlattices or sandwich structures where the layer thicknesses are smaller than the phonon mean free paths. This phenomenon reflects that the redistribution of heat among phonon frequencies to the equilibrium distribution does not occur instantaneously at the interface, rather it develops over some time and distance.