A graphene electron lens

L. Gerhard (1) , E. Moyen (2) , T. Balashov (1) , I. Ozerov (2) , M. Portail (3) , H. Sahaf (2) , L. Masson (2) , W. Wulfhekel (1) , M. Hanbücken (2)

1 KIT - Karlsruhe Institute of Technology
2 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
3 CRHEA - Centre de recherche sur l'hétéroepitaxie et ses applications

An epitaxial layer of graphene was grown on a pre patterned 6H-SiC(0001) crystal. The graphene smoothly covers the hexagonal nano-holes in the substrate without the introduction of small angle grain boundaries or dislocations. This is achieved by an elastic deformation of the graphene by ~0.3% in accordance to its large elastic strain limit. This elastic stretching of the graphene leads to a modification of the band structure and to a local lowering of the electron group velocity of the graphene. We propose to use this effect to focus two-dimensional electrons in analogy to simple optical lenses.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

L. Gerhard, E. Moyen, T. Balashov, I. Ozerov, M. Portail, et al.. A graphene electron lens. Applied Physics Letters, 2012, 100 (19), pp.153106. ⟨10.1063/1.3701594⟩. ⟨hal-00697534⟩