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Raman response of topologically protected surface states in sub‐micrometric Pb 0.77 Sn 0.23 Se flakes
Author(s) -
Mehdipour Sanaz,
LópezDiaz David,
Velázquez María Mercedes,
Hidalgo Pedro,
Méndez Bianchi,
Luna Mónica,
Bellani Vittorio,
Amado Mario,
Balakrishnan Geetha,
Diez Enrique
Publication year - 2020
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5998
Subject(s) - brillouin zone , raman spectroscopy , phonon , overtone , condensed matter physics , electron , materials science , surface states , surface phonon , spectral line , surface (topology) , physics , optics , quantum mechanics , geometry , mathematics
The Raman spectra of the topological crystalline insulator Pb 0.77 Sn 0.23 Se flakes of thickness below 150 nm show the presence of plasma enhanced phonons related to topologically protected surface electronic states. The Fröhlich interaction between the topologically protected surface Dirac electrons and the phonons activates the forbidden phonons near the center of the Brillouin zone. An overtone is observed at a higher wavenumber, with a resonant response with temperature, related to an enhancement of the long‐range coupling between the topologically protected surface electrons and phonons.