Enhanced and tunable asymmetric Imbert–Fedorov and Goos–Hänchen shifts based on epsilon-near-zero response of Weyl semi-metal

Abstract

In this paper, we discuss the Imbert–Fedorov (IF) and Goos–Hänchen (GH) shifts induced by the transverse magnetic polarized light penetrating a bulk Weyl semi-metal (WSM). It is found that the asymmetric IF and GH shifts emerge due to the different energies of left- and right-handed circular polarization components caused by the cross-polarized transmission coefficient t ps. What is more, the asymmetric IF and GH shifts are enhanced significantly at the epsilon-near-zero (ENZ) frequency, where the condition of the transmission coefficients |t ps| = |t pp| is realized because of the decreases in |t pp|. In particular, the ENZ effect can be controlled with the tilt degree of Weyl cones and Fermi energy, thus leading to the enhanced asymmetric IF and GH shifts at different ENZ frequencies. Additionally, the enhanced asymmetric IF and GH shifts show the tunability of the WSM thickness and Weyl node separation. Finally, the enhanced asymmetric IF and GH shifts in the untilted WSM can also be adjusted with the Weyl node separation. Our findings provide easy and available methods to enhance and control the asymmetric IF and GH shifts with a WSM.