▎ 摘　　要

We study graphene quantum point contacts (QPCs) and imaging of the backscattering of the Fermi level wave function by potential introduced by a scanning probe. We consider both etched single-layer QPCs as well as the ones formed by bilayer patches deposited on the sides of the monolayer conducting channel. An atomistic tight-binding method is developed to effectively simulate an infinite graphene plane outside the QPCs using a computational box of a finite size. We demonstrate that in spite of the Klein phenomenon interference effects due to the backscattering at a circular n-p junction induced by the probe potential are visible in spatial conductance maps.