2019 EJRNL PP SIWEI XUE-1.pdf)u
Terbatas Ratnasari
» ITB
Terbatas Ratnasari
» ITB
ZrSiS, an intriguing candidate of topological nodal line semimetals, was discovered to have exotic surface
floating two-dimensional (2D) electrons [Phys. Rev. X 7, 041073 (2017)], which are likely to interact with
surface phonons. Here, we reveal a prominent Kohn anomaly in a surface phonon branch by mapping out
the surface phonon dispersions of ZrSiS using high-resolution electron energy loss spectroscopy. Theoretical
analysis via an electron-phonon coupling (EPC) model attributes the strong renormalization of the surface
phonon branch to the interactions with the surface floating 2D electrons. With the random phase approximation, we calculate the phonon self-energy and evaluate the mode-specific EPC constant by fitting the experimental data. The EPC picture provided here may be important for potential applications of topological nodal line semimetals.