📝 SummarXiv

Abstract

Today's powerful integrated chips for information processing, computer graphics and visualization generate so much heat that liquid based cooling is now indispensable to prevent breakdown from thermal runaway effects. While thermal convection schemes using two-phase cooling in microfluidic networks or liquid immersion are proving effective, further progress requires tackling the intrinsic thermal resistance of a liquid/solid (L/S) interface, quantified by the thermal slip length. Theoretical models and experimental tools for estimating this length have been developed for superfluid/metal interfaces but no comparable tools exist for systems at non-cryogenic temperatures. Researchers have therefore come to rely heavily on non-equilibrium molecular dynamics simulations to understand the influence of various parameters. But despite considerable effort, no actual relations have been proposed. Our study of 180 systems describing a liquid layer confined between identical crystals at different temperatures highlights the influence of correlated behavior throughout the L/S contact zone. When rescaled by key variables in the zone, the data for the thermal slip length exhibit excellent collapse onto two power law relations dependent on the peak value of the in-plane structure factor of the first liquid layer and the ratio of dominant frequencies pegged to the maxima in the vibrational density of states of the first liquid and solid layer. We hope that this perspective, which highlights the critical role of surface localized phonons in L/S systems, can now better guide development of analytic models and de novo interface designs for minimizing thermal slip.