Crossover behavior of the thermal conductance and Kramers' transition rate theory

Published

December 4, 2015

Author(s)

Kirill Velizhanin, Subin Sahu, Chih-Chun Chien, Yonatan Dubi, Michael P. Zwolak

Abstract

Kramers' theory frames chemical reaction rates in solution as reactants overcoming a barrier in the presence of friction and noise. For weak coupling to the solution, the reaction rate is limited by the rate at which the solution can restore equilibrium after a subset of reactants have surmounted the barrier to become products. For strong coupling, there are always sufficiently energetic reactants. However, the solution returns many of the intermediate states back to the reactants before the product fully forms. Here, we demonstrate that the thermal conductance displays an analogous physical response to the friction and noise that drive the heat current through a material or structure. A crossover behavior emerges where the thermal reservoirs dominate the conductance at the extremes and only in the intermediate region are the intrinsic properties of the lattice manifest. Not only does this shed new light on Kramers' classic turnover problem, this result is significant for the design of devices for thermal management and other applications, as well as the proper simulation of transport at the nanoscale.

Citation

Nature - Scientific Reports

Volume

5

Pub Type

Journals

Download Paper

https://doi.org/10.1038/srep17506

Local Download

Keywords

Nanoscale thermal transport, Computational methods, Reaction rates

Citation

Velizhanin, K. , Sahu, S. , Chien, C. , Dubi, Y. and Zwolak, M. (2015), Crossover behavior of the thermal conductance and Kramers' transition rate theory, Nature - Scientific Reports, [online], https://doi.org/10.1038/srep17506, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918545 (Accessed December 26, 2024)