Calculating phase-coherent quantum transport in nanoelectronics with ab initio quasiatomic orbital basis set
Author(s)
Qian, Xiaofeng; Li, Ju; Yip, Sidney
DownloadQian-2010-Calculating phase-co.pdf (1.610Mb)
PUBLISHER_POLICY
Publisher Policy
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Terms of use
Metadata
Show full item recordAbstract
We present an efficient and accurate computational approach to study phase-coherent quantum transport in
molecular and nanoscale electronics. We formulate a Green’s-function method in the recently developed ab
initio nonorthogonal quasiatomic orbital basis set within the Landauer-Büttiker formalism. These quasiatomic
orbitals are efficiently and robustly transformed from Kohn-Sham eigenwave functions subject to the maximal
atomic-orbital similarity measure. With this minimal basis set, we can easily calculate electrical conductance
using Green’s-function method while keeping accuracy at the level of plane-wave density-functional theory.
Our approach is validated in three studies of two-terminal electronic devices, in which projected density of
states and conductance eigenchannel are employed to help understand microscopic mechanism of quantum
transport. We first apply our approach to a seven-carbon atomic chain sandwiched between two finite crosssectioned
Al 001 surfaces. The emergence of gaps in the conductance curve originates from the selection rule
with vanishing overlap between symmetry-incompatible conductance eigenchannels in leads and conductor. In
the second application, a 4,4 single-wall carbon nanotube with a substitutional silicon impurity is investigated.
The complete suppression of transmission at 0.6 eV in one of the two conductance eigenchannels is
attributed to the Fano antiresonance when the localized silicon impurity state couples with the continuum states
of carbon nanotube. Finally, a benzene-1,4-dithiolate molecule attached to two Au 111 surfaces is considered.
Combining fragment molecular orbital analysis and conductance eigenchannel analysis, we demonstrate that
conductance peaks near the Fermi level result from resonant tunneling through molecular orbitals of benzene-
1,4-dithiolate molecule. In general, our conductance curves agree very well with previous results obtained
using localized basis sets while slight difference is observed near the Fermi level and conductance edges.
Date issued
2010-11Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering; Massachusetts Institute of Technology. Department of Nuclear Science and EngineeringJournal
Physical review B
Publisher
American Physical Society
Citation
Qian, Xiaofeng, Ju Li, and Sidney Yip. “Calculating phase-coherent quantum transport in nanoelectronics with ab initio quasiatomic orbital basis set.” Physical Review B 82.19 (2010) : n. pag. © 2010 The American Physical Society
Version: Final published version
ISSN
1098-0121
1550-235X