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Energy‐resolved STM maps of finite carbon nanotubes and the role of surface–tube interactions
Author(s) -
De Menech Mario,
Saalmann Ulf,
Garcia Martin E.
Publication year - 2010
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200945486
Subject(s) - carbon nanotube , reflection (computer programming) , materials science , scattering , dispersion relation , tube (container) , condensed matter physics , molecular physics , symmetry (geometry) , perpendicular , dispersion (optics) , optics , physics , geometry , nanotechnology , composite material , mathematics , computer science , programming language
The influence of the supporting surface on the standing wave electronic modes of finite metallic carbon nanotubes (CNTs) is discussed. The charge distribution of the states is visualized by simulating the energy resolved scanning tunneling spectroscopy (STS) maps. The Fourier transform of the spatial patterns exhibited by the STS maps allows to reconstruct the dispersion relation, whose definiteness is smeared out for increasing surface–tube interaction strengths. The scattering of the modes in the tube due to the interaction with the surface causes distortions of the simulated maps. For example, the reflection symmetry with respect to the mirror plane perpendicular to the tube axis appears to be broken for modes in the case of narrow tubes, when the interaction with the surface is strong enough. Breaking of the reflection symmetry: STS map for a (4,4) carbon nanotube of length 50 a 0 near the Fermi level placed at 2.5 Å (upper tube) and 3.0 Å (lower tube) away from an Au(111) surface. Red, green, and blue colored regions refer to large, intermediate and low values of the current, respectively.