  We study the rectification of near-field radiative heat transfer between two
InSb nano-particles due to the presence of non-reciprocal surface modes in a
nearby InSb sample when an external magnetic field is applied and its
dependence on the magnetic field strength. We reveal the spin-spin coupling
mechanism of the localized particle resonances and the surface mode resonances
which is substantiated by the directional heat flux in the given setup. We
discuss further the interplay of the frequency shift, the propagation length,
and local density of states on the strength and directionality of the
rectification as well as the non-reciprocal heating effect of the
nanoparticles.
