Plasmonic Tuning of the Near Field Heat Transfer in Double Layer Graphene

TL;DR

This paper investigates non-radiative heat transfer in double layer graphene, revealing that plasmon modes dominate at neutrality and can be tuned via electrostatic doping, leading to efficient heat exchange at low temperatures.

Contribution

It provides analytic expressions for heat current in double layer graphene and demonstrates tunability of heat transfer through electrostatic doping.

Findings

Heat exchange dominated by inter-layer plasmon modes at neutrality.

Graphene layers outperform metals in heat transfer efficiency at low temperatures.

Electrostatic doping suppresses plasmonic heat transfer, enabling tunability.

Abstract

We discuss the non-radiative heat transfer in non-equilibrium double layer graphene system. We show that at the neutrality point the heat exchange is dominated by the inter-layer plasmon modes and derive analytic expressions for the heat current as a function of temperature and the interlayer separation. These results show that for a range of low temperatures the two graphene layers are much more efficient heat exchanger than conventional metals. The physical reason behind this phenomenon is the presence of inter-band excitations with a large energy, and a small momentum in graphene spectrum. Plasmonic mechanism of the heat transfer is sharply suppressed by electrostatic doping. This allows for tuning of the heat exchange by a small applied voltage between the two layers.