Near-field thermal rectification driven by nonreciprocal hyperbolic surface plasmons

In this work, we theoretically demonstrate a pathway for highly efficient near-field thermal rectification. We propose the use of nonreciprocal hyperbolic surface plasmon polaritons (NHSPPs) supported by a drift-biased graphene grating to rectify the radiative heat flux between the two dielectric particles. At higher chemical potentials, we achieve theoretical rectification ratios over 88.67, which is a 460-fold improvement over the case of a drift-biased graphene sheet. By adjusting the value of the drift current or the orientation of the graphene ribbons, the NHSPPs can be actively manipulated, hence inducing the modulation of the rectification effect. We discuss the influence of the filling ratio of the grating and the height of the particles from its surface on the near-field radiative heat transfer. We find that the rectification ratio and the heat flux between the particles can be adjusted over a broad range by controlling the height of the particles. Compared with a drift-biased graphene sheet, the directional stability of the diode was also enhanced. This work provides an idea for the thermal management of micro-and nanoscale devices. (c) 2021 Elsevier Ltd. All rights reserved.