Nonreciprocal radiative heat transfer between two planar bodies
Lingling Fan, Yu Guo, Georgia T. Papadakis, Bo Zhao, Zhexin Zhao, Siddharth Buddhiraju, Meir Orenstein, Shanhui Fan
Abstract
We study the consequence of breaking reciprocity within the context of near-field radiative heat transfer between two planar bodies. Our findings introduce a thermodynamic constraint, which states that the heat transferred from one planar body to another at each frequency and in-plane wave vector is unchanged upon interchanging the two bodies, regardless of whether the materials are reciprocal or not. We further identify a unique signature of nonreciprocity, which is the breaking of the symmetry of the heat flux density between positive and negative in-plane wave vectors. We numerically demonstrate our findings in an example system consisting of magneto-optical materials. Our formalism applies to both near- and far-field regimes, opening opportunities for exploiting nonreciprocity in two-body radiative heat transfer systems.