TY - JOUR

T1 - Interplay between quantum interference and conformational fluctuations in single-molecule break junctions

AU - Berritta, Marco

AU - Manrique, David Zsolt

AU - Lambert, Colin J.

PY - 2015/1/21

Y1 - 2015/1/21

N2 - We theoretically explored the combined role of conformational fluctuations and quantum interference in determining the electrical conductance of single-molecule break junctions. In particular we computed the conductance of a family of methylsulfide-functionalized trans-alpha,omega-diphenyloligoene molecules, with terminal phenyl rings containing meta or para linkages, for which (at least in the absence of fluctuations) destructive interference in the former is expected to decrease their electrical conductance compared with the latter. We compared the predictions of density functional theory (DFT), in which fluctuational effects are absent, with results for the conformationally-averaged conductance obtained from an ensemble of conformations obtained from classical molecular dynamics. We found that junctions formed from these molecules exhibit distinct transport regimes during junction evolution and the signatures of quantum interference in these molecules survive the effect of conformational fluctuations. Furthermore, the agreement between theory and experiment is significantly improved by including conformational averaging.

AB - We theoretically explored the combined role of conformational fluctuations and quantum interference in determining the electrical conductance of single-molecule break junctions. In particular we computed the conductance of a family of methylsulfide-functionalized trans-alpha,omega-diphenyloligoene molecules, with terminal phenyl rings containing meta or para linkages, for which (at least in the absence of fluctuations) destructive interference in the former is expected to decrease their electrical conductance compared with the latter. We compared the predictions of density functional theory (DFT), in which fluctuational effects are absent, with results for the conformationally-averaged conductance obtained from an ensemble of conformations obtained from classical molecular dynamics. We found that junctions formed from these molecules exhibit distinct transport regimes during junction evolution and the signatures of quantum interference in these molecules survive the effect of conformational fluctuations. Furthermore, the agreement between theory and experiment is significantly improved by including conformational averaging.

KW - CHARGE-TRANSPORT

KW - ELECTRONIC TRANSPORT

KW - CONDUCTANCE

KW - DEPENDENCE

KW - PARALLEL

KW - WIRES

KW - INTERFACE

KW - EVOLUTION

KW - DYNAMICS

KW - SYMMETRY

U2 - 10.1039/c4nr05316h

DO - 10.1039/c4nr05316h

M3 - Journal article

VL - 7

SP - 1096

EP - 1101

JO - Nanoscale

JF - Nanoscale

SN - 2040-3364

IS - 3

ER -