title: Interaction-induced negative differential resistance in asymmetric molecular junctions.
abstract: Combining insights from quantum chemistry calculations with master equations, we discuss a mechanism for negative differential resistance (NDR) in molecular junctions, operated in the regime of weak tunnel coupling. The NDR originates from an interplay of orbital spatial asymmetry and strong electron-electron interaction, which causes the molecule to become trapped in a nonconducting state above a voltage threshold. We show how the desired asymmetry can be selectively introduced in individual orbitals in, e.g., oligo(phenyleneethynylene)-type molecules by functionalization with a suitable side group, which is in linear conjugation to one end of the molecule and cross-conjugated to the other end.
authors.affiliation: Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen Ø, Denmark. leijnse@fys.ku.dk
authors.forename: M
authors.initials: M
authors.lastname: Leijnse
authors.forename: W
authors.initials: W
authors.lastname: Sun
authors.forename: M Brøndsted
authors.initials: MB
authors.lastname: Nielsen
authors.forename: P
authors.initials: P
authors.lastname: Hedegård
authors.forename: K
authors.initials: K
authors.lastname: Flensberg