Electrically controlled and directional-dependent Goos-Hänchen shift in a non-Hermitian multilayered structure with Dirac semimetal

Directional-dependent Goos-H a¨ nchen (GH) shift describes its dependence on the propagation direction of the incident wave. That is to say, the GH shifts are different when the incident wave propagates along two opposite directions (we call them the forward and backward incidence later). We demonstrate, using the transfer matrix method and stationary phase method, that the multilayered structure with the recently advanced Dirac semimetal can realize the directional-dependent GH shift. It is found that the maximum absolute value of the GH shift for the forward incidence is just 22 times of the incident wavelength (22λ) but it is up to 2286λ for the backward incidence. We clarify the mechanism behind the directional-dependence of the GH shift in the multilayered structure and highlight that the mirror asymmetry of this structure is the dominated factor to produce this kind of directional dependent optical effect. Our work allows the unique chance of the multilayered structure with Dirac semimetal for producing the directional-dependent GH shift and designing the directional devices, such as, directional amplifier, unidirectional couplers and splitters.