Simulating STM transport in alkanes from first principles
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2009Access:
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C. Toher, I. Rungger, and S. Sanvito, Simulating STM transport in alkanes from first principles, Physical Review B, 79, 2009, 205427Download Item:
PhysRevB.79.205427.pdf (Published (publisher's copy)) 513.1Kb
Abstract:
Simulations of scanning tunneling microscopy
STM
measurements for molecules on surfaces are tradi-
tionally based on a perturbative approach, most typically employing the Tersoff-Hamann method. This assumes
that the STM tip is far from the sample so that the two do not interact with each other. However, when the tip
gets close to the molecule to perform measurements, its electrostatic interplay with the substrate may generate
nontrivial potential distribution, charge transfer, and forces, all of which may alter the electronic and physical
structure of the molecule. These effects are investigated with the
ab initio
quantum transport code
SMEAGOL
,
combining the nonequilibrium Green?s-function formalism with density functional theory. In particular, we
investigate alkanethiol molecules terminated with either CH
3
or CF
3
end-groups on gold surfaces for which
recent experimental data are available. We discuss the effects connected to the interaction between the STM tip
and the molecule, as well as the asymmetric charge transfer between the molecule and the electrodes
Sponsor
Grant Number
Science Foundation Ireland (SFI)
07/IN.1/I945
Author's Homepage:
http://people.tcd.ie/sanvitosDescription:
PUBLISHED
Author: SANVITO, STEFANO; RUNGGER, IVAN
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Physical Review B79
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PhysicsSubject (TCD):
Nanoscience & MaterialsDOI:
http://dx.doi.org/10.1103/PhysRevB.79.205427Licences: