Bidirectional and Unidirectional Negative Differential Thermal Resistance Effect in a Modified Lorentz Gas ModelSupported by the National Natural Science Foundation of China (Grant Nos. 11975125 and 21803031), the Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. KYCX20 1229), and the Natural Science Foundation of the Jiangsu Higher Education Institution of China (Grant No. 18KJB150022).

Abstract

Recently, the negative differential thermal resistance effect was discovered in a homojunction made of a negative thermal expansion material, which is very promising for realizing macroscopic thermal transistors. Similar to the Monte Carlo phonon simulation to deal with grain boundaries, we introduce positive temperature-dependent interface thermal resistance in the modified Lorentz gas model and find negative differential thermal resistance effect. In the homojunction, we reproduce a pair of equivalent negative differential thermal resistance effects in different temperature gradient directions. In the heterojunction, we realize the unidirectional negative differential thermal resistance effect, and it is accompanied by the super thermal rectification effect. Using this new way to achieve high-performance thermal devices is a new direction, and will provide extensive reference and guidance for designing thermal devices.