Negative differential thermal resistance effect in a macroscopic homojunction

The negative differential thermal resistance (NDTR) effect is an important mechanism to realize a thermal transistor that is of great significance to realize thermal control. We find that with accompanying an interface thermal resistance (ITR), which has a certain temperature-dependence, the macroscopic homojunction can present a NDTR. The temperature-dependent ITR to achieve NDTR can be realized by using materials with negative thermal expansion. As an example, a NDTR in the silicon homojunction was found at low temperature. The discovery of macro-NDTR will pave the way to design a macroscopic thermal transistor and also help us manipulate thermal flow more freely and effectively.