Dispersion of the surface phonons in semiconductor/topological insulator Si/Bi2Te3 heterostructure studied by high resolution Brillouin spectroscopy
Journal article, 2021

The dynamics and dispersion of surface phonons in heterostructure semiconductor/ topological insulator Si/Bi2Te3 was investigated using high resolution Brillouin light scattering method in the GHz frequency range. Both Rayleigh and Sezawa surface acoustic waves have been observed for wave vectors ranging from 0.006 to 0.023 nm−1. Anomaly in dispersion relations ω(q) for both surface waves were detected for the wave vector q = 0.016 nm−1. The finite element method (FEM) was used to simulate the observed shapes of ω(q) and to find the deformation profiles of surface acoustic waves. We attribute the observed changes to the coupling between low energy electrons and surface phonons. The coupling between helical Dirac states and surface phonons is discussed in the frame of accessible theoretical models.

Topological insulator

Finite Element Method

Surface phonons

Brillouin spectroscopy

Electron phonon coupling

Rayleigh and Sezawa waves

Elastic properties

Author

A. Trzaskowska

Adam Mickiewicz University in Poznań

S. Mielcarek

Adam Mickiewicz University in Poznań

M. Wiesner

Adam Mickiewicz University in Poznań

Floriana Lombardi

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

B. Mroz

Adam Mickiewicz University in Poznań

Ultrasonics

0041-624X (ISSN)

Vol. 117 106526

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics

DOI

10.1016/j.ultras.2021.106526

More information

Latest update

8/26/2021