Emergence of orbital angular momentum due to broken inversion symmetry and its contribution to Rashba-type splitting

ORAL

Abstract

We demonstrate that the chiral orbital angular momentum (OAM) structure can emerge as a result of broken inversion symmetry especially at the metal surfaces. The surface-normal electric field is responsible for chiral OAM states even if spin-orbit interaction is negligible. Such chiral OAM structure can be measured by a circular dichroism (CD) in angle-resolved photoemission spectroscopy (ARPES). To confirm the existence of OAM and its detection by CD-ARPES, we perform simulation of CD-ARPES for Cu surface states by first-principles calculation and the results agree well with our CD-ARPES experiment. Addition of the spin-orbit interaction to the chiral OAM structure produces a chiral spin angular momentum (SAM) pattern and the corresponding Rashba-type band splitting. We assert that OAM polarization should be a more widespread feature than the chiral spin structure which requires strong spin-orbit coupling.

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Authors

  • Choong H. Kim

    • Seoul National University, Seoul, Korea

  • Jin-Hong Park

    • Sungkyunkwan University, Suwon, Korea

  • Seung Ryong Park

    • University of Colorado at Boulder, Boulder, Colorado, USA

  • Beom Young Kim

    • Yonsei University, Seoul, Korea

  • Jaejun Yu

    • Seoul National University, Seoul, Korea

  • Changyoung Kim

    • Yonsei University, Seoul, Korea

  • Jung Hoon Han

    • Department of Physics and BK21 Physics Research Division, Sungkyunkwan University, Suwon 440-746, Korea
    • Sungkyunkwan University
    • Sungkyunkwan University, Suwon, Korea