Anisotropic Light-Matter Interactions in Single Crystal Topological Insulator Bismuth Selenide

TL;DR

This study uses angle-resolved polarized Raman spectroscopy to explore anisotropic light-matter interactions in single-crystal Bi2Se3, revealing electron-phonon interactions and polarization dependencies related to its crystallographic structure.

Contribution

It provides detailed Raman tensor analysis of Bi2Se3, highlighting anisotropic interactions and polarization effects in a topological insulator material.

Findings

Higher differential polarizability along the cross-plane (bc-plane).

Evidence of fundamental electron-phonon interactions.

Distinct anisotropic light-matter interaction patterns.

Abstract

Anisotropy of light-matter interactions in materials give remarkable information about the phonons and their interactions with electrons. We report the angle-resolved polarized Raman spectroscopy of single-crystal of Bi2Se3 to obtain the elements of Raman tensor for understanding the strength of polarization along different crystallographic orientations. Intensity variation in the polar plots corresponding to E_g^1 ~ 37 cm-1, A_1g^1 ~71 cm-1, E_g^2 ~ 130 cm-1, and A_1g^2 ~ 173 cm-1 suggests the higher differential polarizability along cross-plane (bc-plane). The polar patterns and the differences in elements of the Raman tensor provides the evidence of the fundamental electron-phonon and anisotropic light matter interactions in Bi2Se3.