Bidirectional and Unidirectional Negative Differential Thermal Resistance Effect in a Modified Lorentz Gas Model

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.