Electron flow in circular n-p junctions of bilayer graphene
WoS ID: 000269638900088
Scopus ID: 70349146682
We present a theoretical study of electron wave functions in ballistic circular n-p junctions of bilayer graphene. Similarly to the case of a circular n-p junction of monolayer graphene, we find that (i) the wave functions form caustics inside the circular region and (ii) the shape of these caustics are well described by a geometrical optics model using the concept of a negative refractive index. In contrast to the monolayer case, we show that the strong focusing effect is absent in the bilayer. We explain these findings in terms of the angular dependence of Klein tunneling at a planar n-p junction.