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Title: Theory of molecular conductance using a modular approach

This paper probes the correlation between the conductance of a molecular wire (the property of a whole system) and its constituent backbone units (modules). By using a tight-binding Hamiltonian combined with single-particle Green’s functions, we develop an approach that enables an estimate of a conductance decay constant in terms of the Hamiltonians of molecular backbone units and the couplings between two nearest-neighbor units in the off-resonant tunneling regime. For demonstration, we examine several representative molecular systems in a framework of the Hückel model (the simplest atomistic-level model). The Hückel model can be reduced to a single-orbital-per-site formulation [A. Nitzan, Annu. Rev. Phys. Chem. 52, 681 (2001)], and each energy level in the single-orbital-per-site picture can be expressed in an explicit form including the synergistic effect of all molecular orbitals of a molecular backbone unit. Finally, based on the proposed approach, we show the correspondence between the complete destructive quantum interference and an infinite injection gap and derive the preconditions of the modified Simmons equation and the rule of intramolecular series circuits.
Authors:
ORCiD logo [1] ; ORCiD logo [1]
  1. Princeton Univ., NJ (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
FG02-02ER15344; CHE-1058644; W911NF-13-1-0237
Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 145; Journal Issue: 23; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Research Org:
Princeton Univ., NJ (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); US Army Research Office (ARO)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; hopping transport; tunneling; eigenvalues; electrodes; transport properties; Green's function methods; Fermi levels; integrated circuits; quantum interference
OSTI Identifier:
1465674
Alternate Identifier(s):
OSTI ID: 1336499