Strong enhancement of near-field radiative heat transfer between anisotropic magneto-optical gratings by a weak magnetic field

Abstract

The highly tunable surface magneto-plasmon polaritons supported by magneto-optical materials provide reliable means for active adjusting of near-field radiative heat transfer (NFRHT). In our study, we proposed an anisotropic system consisting of two graphene-covered magneto-optical gratings, and theoretically investigate the NFRHT between them controlled by a weak magnetic field. We find that an external magnetic field open a broad-spectrum photo tunneling channel and modify the energy distribution of surface electromagnetic modes in the wave-vector space. The near-field heat flux between two magneto-optical gratings can achieve a remarkable maximum enhancement of 6 times at the magnetic field H=0.9T compared to that without a magnetic field. Owing to the coupling between highly tunable surface magneto-plasmon polaritons of graphene and surface modes of InSb, the regulation ratio of the heat flux exceeds 10 from 0.5 T to 0.9 T. In addition, the effects of the separation distance, chemical potential of graphene and structural configuration of two gratings are also investigated. We look forward to the proposed system being used as a thermal switch, providing convenience for tuning thermal radiation and improving the efficiency of energy-utilization devices.