Tunable and nonreciprocal Goos–Hänchen shifts on reflection from a graphene-coated gyroelectric slab

• The GH shifts have higher light intensity in the proposed structure.
• The GH shifts can be tuned by graphene's chemical potential and magnetic field.
• At grazing incidence, the large and negative SGH shifts occur in the THz region.
• The external magnetic field leads to nonreciprocal GH shifts.

We study the Goos–Hänchen (GH) shifts of a reflected Gaussian beam from a graphene-coated gyroelectric slab. The reflection coefficient is derived by using the transfer-matrix method and the spatial Goos–Hänchen (SGH) shift and angular Goos–Hänchen (AGH) shift are determined in terms of stationary-phase approach. The effects of graphene's chemical potential, external magnetic field, the thickness of the slab and the frequency of incident beam on the SGH and AGH shifts are analyzed and discussed numerically. At grazing incidence, the large, tunable and nonreciprocal SGH shifts with higher light intensity are achieved in the terahertz region, which might be useful for the development of various tunable terahertz-wave devices.