Near-Field Radiative Heat Transfer between Drift-biased Graphene through Nonreciprocal Surface Plasmons

TL;DR

This paper theoretically demonstrates that applying a drift current to graphene enables nonreciprocal surface plasmons polaritons, which can modulate and enhance near-field radiative heat transfer, offering new control mechanisms for energy systems.

Contribution

It introduces the concept of nonreciprocal surface plasmons polaritons in drift-biased graphene as a novel mode for controlling near-field heat transfer.

Findings

NSPPs enable asymmetric heat transfer depending on drift current direction.

Coupling of NSPPs varies with vacuum gap size, affecting nonreciprocity.

Drift current significantly influences heat flux at low chemical potential.

Abstract

In this Rapid Communication, we theoretically demonstrate that near-field radiative heat transfer (NFRHT) can be modulated and enhanced by a new energy transmission mode of evanescent wave, i.e. the nonreciprocal surface plasmons polaritons (NSPPs). In addition to the well-known coupled surface plasmon polaritons (SPPs), applying a drift current on a graphene sheet leads to an extremely asymmetric photonic transmission model, which has never been noted in the noncontact heat exchanges at nanoscale before. The coupling of plasmons in the infrared bands dominates the NFRHT, associated with low loss (high loss and ultrahigh confinement) traveling along (against) the current. The dependence of NSPPs on the drift-current velocity as well as the vacuum gap is analyzed. It is found that the coupling of NSPPs at smaller and larger gap sizes exhibits different nonreciprocities. Finally, we also demonstrate that the prominent influence of the drift current on the radiative heat flux is found at a low chemical potential. These findings will open a new way to spectrally control NFRHT, which holds great potential for improving the performance of energy systems like near-field thermophotovoltaics and thermal modulator.