Quantized thermal transport of surface plasmon polaritons along metal nanowires

The surface plasmon polariton (SPP) has emerged as a new heat dissipation channel along metallic nanofilms in recent years. In this work, we investigate the SPP heat transport along metallic nanowires based on a kinetic theoretical model. We demonstrate quantized thermal transport of SPPs around room temperature with a universal quantum independent of metallic type, and appreciable SPP thermal conductivity around 10% of the electronic counterpart at room temperature in a gold nanowire with a diameter of 10 nm and a length of 20 μm. The temperature dependence of the dielectric function of gold is shown to be important in modeling the SPP heat transport at elevated temperatures due to the decrease of propagation length with increasing temperature. We also show that the silver nanowire has larger SPP thermal conductivity than gold nanowire under the same conditions. This work will thus promote the fundamental study of quantum heat transport in nano-systems as well as the practical application of SPPs in thermal management of micro- and nano-electronic devices.