Prediction of quantum interference in molecular junctions using a parabolic diagram: Understanding the origin of Fano and anti-resonances

Daijiro Nozaki, Stanislav M. Avdoshenko, Haldun Sevincli, Rafael Gutierrez, Gianaurelio Cuniberti

    Research output: Contribution to journalConference articleResearchpeer-review

    Abstract

    Recently the interest in quantum interference (QI) phenomena in molecular devices (molecular junctions) has been growing due to the unique features observed in the transmission spectra. In order to design single molecular devices exploiting QI effects as desired, it is necessary to provide simple rules for predicting the appearance of QI effects such as anti-resonances or Fano line shapes and for controlling them. In this study, we derive a transmission function of a generic molecular junction with a side group (T-shaped molecular junction) using a minimal toy model. We developed a simple method to predict the appearance of quantum interference, Fano resonances or anti- resonances, and its position in the conductance spectrum by introducing a simple graphical representation (parabolic model). Using it we can easily visualize the relation between the key electronic parameters and the positions of normal resonant peaks and anti-resonant peaks induced by quantum interference in the conductance spectrum. We also demonstrate Fano and anti-resonance in T-shaped molecular junctions using a simple tight-binding model. This parabolic model enables one to infer on-site energies of T-shaped molecules and the coupling between side group and main conduction channel from transmission spectra.
    Original languageEnglish
    Article number012013
    Book seriesJournal of Physics: Conference Series (Online)
    Volume427
    ISSN1742-6596
    DOIs
    Publication statusPublished - 2013
    Event5th interdisciplinary conference on Progress in Nonequilibrium Green's Functions (PNGF5) - University of Jyväskylä, Jyväskylä, Finland
    Duration: 27 Aug 201231 Aug 2012
    Conference number: 5

    Conference

    Conference5th interdisciplinary conference on Progress in Nonequilibrium Green's Functions (PNGF5)
    Number5
    LocationUniversity of Jyväskylä
    CountryFinland
    CityJyväskylä
    Period27/08/201231/08/2012

    Keywords

    • Forecasting
    • Green's function
    • Plasma diagnostics
    • Quantum interference devices
    • Resonance

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