Existence of negative differential thermal conductance in one-dimensional diffusive thermal transport

摘要

We show that in a finite one-dimensional (1D) system with diffusive thermal transport described by thenFourier’s law, negative differential thermal conductance (NDTC) cannot occur when the temperature at one endnis fixed and there are no abrupt junctions. We demonstrate that NDTC in this case requires the presence ofnjunction(s) with temperature-dependent thermal contact resistance (TCR). We derive a necessary and sufficientncondition for the existence of NDTC in terms of the properties of the TCR for systems with a single junction.nWe show that under certain circumstances we even could have infinite (negative or positive) differential thermalnconductance in the presence of the TCR. Our predictions provide theoretical basis for constructing NDTC-basedndevices, such as thermal amplifiers, oscillators, and logic devices.