Large spatial shifts of reflective beam at the surface of graphene/hBN metamaterials

We theoretically studied the Goos-Hänchen (GH) and Imbert-Fedorov (IF) shifts of reflective beam at the surface of graphene/hBN metamaterials. The results show that the GH-shift is significantly enhanced and also possesses the large reflectivity when the light beam is incident at the critical angle near the Brewster angle. We found that the IF-shift is the largest when the reflective beam is a special polarized-beam or the reflective coefficients satisfy the conditions |r_s | = |r_p | and φ_s - φ_p = 2jπ (j is an integer). By changing the chemical potential, filling ratio and tilted angle, the position and width of frequency windows obtaining the maximum values of shifts can be effectively adjusted. The large and tunable GH- and IF-shifts with the higher reflectivity provide an alternative scheme to develop new nano-optical devices.