Mid-infrared broadband nonreciprocal thermal radiation involving patterned Weyl semimetal

A mid-infrared broadband nonreciprocal thermal emitter, composed of a patterned Weyl semimetal placed above a metallic mirror, has been designed and studied. The findings indicate that significant nonreciprocal radiation is achieved within the spectral range of 15–16.5 μm, with an average nonreciprocity exceeding 0.82. The underlying physical origin is elucidated through examining the magnetic field distribution at a selected resonance, revealing that the broadband nonreciprocity originates from guided mode resonance. Additionally, the sensitivity of the broadband nonreciprocity to the angle of incidence and structural parameters has been explored, demonstrating that broadband nonreciprocity remains stable over a broad parameter range, which is beneficial for real manufacture and applications. It is anticipated that the approach outlined here will advance the development of innovative energy conversion and capture systems and sophisticated thermal management technologies.