Tunable Fano resonance in a one-dimensional photonic crystal containing a Weyl semimetal

Abstract

Fano resonances are widely utilized in the design of low-power all-optical switches, optical sensors and nonlinear optical devices. Although various nanostructures support Fano resonances, the lack of mechanisms for linear tuning of Fano resonance has become a limitation. In this paper, we propose a heterostructure consisting of a single layer of Weyl semimetal (WSM) and a one-dimensional photonic crystal (1DPC). Owing to the interference between the discrete state supported by the single layer of WSM and the continuous states supported by the 1DPC, a Fano resonance occurs. Besides, both the position and the line shape of the Fano resonance can be tuned by the Fermi energy, the distance between two Wely cones, and the tilt parameter of the WSM, the number of periods of the 1DPC, and the incident angle. With the assistance of the Fano resonance, a large Goos-Hänchen shift can be achieved. This work may offer greater possibilities to explore the applications of Fano resonances, including high-performance sensors and narrowband filters.