Local enhancement of inelastic tunnelling in epitaxial graphene on SiC(0001)

0353074 - FZÚ 2011 RIV DE eng J - Journal Article
Červenka, Jiří - van de Ruit, K. - Flipse, C.F.J.
Local enhancement of inelastic tunnelling in epitaxial graphene on SiC(0001).
Physica Status Solidi B. Roč. 247, 10-12 (2010), s. 2992-2996. ISSN 0370-1972. E-ISSN 1521-3951
Institutional research plan: CEZ:AV0Z10100521
Keywords : graphene * phonons * scanning tunnelling microscopy * silicon carbide
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.344, year: 2010

We have measured the elastic and inelastic tunnelling properties of epitaxial graphene on SiC(0001) using cryogenic scanning tunnelling spectroscopy. We find that the dominant inelastic channel of the out-of-plane acoustic graphene phonon at 70mV is spatially localized to particular regions of the graphene–SiC system that contain localized states. At these locations the maximum inelastic tunnelling channel reaches up to half of the total tunnelling current. The local enhancement of the inelastic tunnelling is found at the localized electron states of the graphene/SiC interface layer. Nonequilibrium Green’s function formalism theory calculations indicate that this intense inelastic channel arises from graphene phonon modes strongly coupled to narrow electron states.
Permanent Link: http://hdl.handle.net/11104/0192418