Adjustable spin-dependent perfect absorption via topological edge state in a heterostructure with the multi-Weyl semimetal

Abstract

Chiral optical absorption is a particular phenomenon in the structure with broken symmetry, which holds wide values in filtering, photodetection, multiplexed holograms, and numerous other aspects. However, an external magnetic field is generally required to acquire the symmetry breaking chiral composition. Fortunately, the Weyl semimetals with intrinsic time-reversal symmetry breaking properties reveal available schemes to discuss the chiral optical absorption without an applied magnetic field. Here, we present a topological one-dimensional photonic crystal heterostructure inserted by a multi-Weyl semimetal (mWSM) film to discuss the spin-dependent optical absorption. It is indicated that due to the excited topological edge state (TES) mode and the Hall conductivity of the mWSM, the perfect absorption (PA) of left-hand circular polarization (LCP) and right-hand circular polarization (RCP) lights can be obtained at distinct frequencies. Furthermore, the PA frequency of LCP and RCP lights can be adjusted via the tilt degree of Weyl cones, Fermi energy, topological charge, Weyl node separation, and incident angle. The research refers an available and efficient scheme to acquire the adjustable spin-dependent PA without an external magnetic field and might develop potential values in spin-dependent photonic aspects.