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Updated: Apr 18, 2026
Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
Thickness tunable quantum interference between surface phonon and Dirac plasmon states in thin films of the
Yuri D Glinka1, Sercan Babakiray, Trent A Johnson
1Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506-6315, USA. Institute of Physics, National Academy of Sciences of Ukraine, Kiev 03028, Ukraine.
Abstract:
We report on a >100-fold enhancement of Raman responses from Bi2Se3 thin films if laser photon energy switches from 2.33 eV (532 nm) to 1.58 eV (785 nm), which is due to direct optical coupling to Dirac surface states (SS) at the resonance energy of ∼1.5 eV (a thickness-independent enhancement) and due to nonlinearly excited Dirac plasmon (a thickness-dependent enhancement). Owing to the direct optical coupling, we observed an in-plane phonon mode of hexagonally arranged Se-atoms associated with a continuous network of Dirac SS. This mode revealed a Fano lineshape for films <15 nm thick, resulting from quantum interference between surface phonon and Dirac plasmon states.
