Spin Selectivity in Photoelectron Transmission through Self-Assembled Monolayers of Mercurated DNA Helices

POSTER

Abstract

Chiral molecules have been shown to act as electron spin filters at room temperature, however the mechanisms remain elusive. Molecular spin-orbit coupling is thought to play a dominant role due to the chiral electrostatic potential that breaks inversion symmetry experienced by transmitted electrons. To test this hypothesis, we designed helical DNA molecules that contain mercury atoms bound at base-pair mismatches. By controlling the number and location of mercury atoms along the DNA axis, we manipulate the strength of the helical spin-orbit field via the heavy atom effect. Monolayers of mercurated DNA are formed on ferromagnetic substrates. Using ultraviolet photoemission spectroscopy, efficiencies of electron transmission through DNA monolayers is probed. Photoelectrons from ferromagnetic surfaces are spin polarized, while adsorbed chiral molecules act as spin filters. Thus, emission intensities and energies of the secondary-electron cutoff are compared using DNA monolayers with varying mercury content. Demonstrating control over molecular spin-orbit coupling to tune spin selectivity by chiral molecules is critical to assess their practically for spintronics applications.

*We gratefully acknowledge NSF ECCS grant #1509794 and NSF DMR grant #1312750 for support of this work.

Presenters

  • John Abendroth

    • California NanoSystems Institute, Univ of California - Los Angeles

Authors

  • John Abendroth

    • California NanoSystems Institute, Univ of California - Los Angeles

  • Matthew Ye

    • California NanoSystems Institute, Univ of California - Los Angeles

  • Dominik Stemer

    • California NanoSystems Institute, Univ of California - Los Angeles

  • Kevin Cheung

    • California NanoSystems Institute, Univ of California - Los Angeles

  • Mohammed El Hadri

    • Center for Memory and Recording Research, University of California, San Diego
    • Center for Memory and Recording Research, Univ of California - San Diego

  • Eric Fullerton

    • Center for Memory Research, Univ of California - San Diego
    • University of California San Diego
    • University of California, San Diego
    • Center for Memory and Recording Research, University of California, San Diego
    • Center for Memory Recording Research, University of California San Diego
    • Center for Memory and Recording Research, University of California San Diego
    • Center for Memory and Recording Research, Univ of California - San Diego

  • Paul Weiss

    • Univ of California - Los Angeles
    • Chemistry & Biochemistry, Univ of California - Los Angeles
    • California NanoSystems Institute, Univ of California - Los Angeles