Molecular spintronics: Destructive quantum interference controlled by a gate

Aldilene Saraiva-Souza*, Manuel Smeu, Lei Zhang, Antonio Gomes Souza Filho, Hong Guo, Mark A. Ratner

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Scopus citations

Abstract

The ability to control the spin-transport properties of a molecule bridging conducting electrodes is of paramount importance to molecular spintronics. Quantum interference can play an important role in allowing or forbidding electrons from passing through a system. In this work, the spin-transport properties of a polyacetylene chain bridging zigzag graphene nanoribbons (ZGNRs) are studied with nonequilibrium Greens function calculations performed within the density functional theory framework (NEGF-DFT). ZGNR electrodes have inherent spin polarization along their edges, which causes a splitting between the properties of spin-up and spin-down electrons in these systems. Upon adding an imidazole donor group and a pyridine acceptor group to the polyacetylene chain, this causes destructive interference features in the electron transmission spectrum. Particularly, the donor group causes a large antiresonance dip in transmission at the Fermi energy EF of the electrodes. The application of a gate is investigated and found to provide control over the energy position of this feature making it possible to turn this phenomenon on and off. The current-voltage (I-V) characteristics of this system are also calculated, showing near ohmic scaling for spin-up but negative differential resistance (NDR) for spin-down.

Original languageEnglish (US)
Pages (from-to)15065-15071
Number of pages7
JournalJournal of the American Chemical Society
Volume136
Issue number42
DOIs
StatePublished - Oct 22 2014

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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