Anisotropic light-matter interactions in the single-crystal topological insulator bismuth selenide

Anisotropy of light-matter interactions in materials gives remarkable information about phonons and their interactions with electrons. We report angle-resolved polarization Raman spectroscopy of single crystal of Bi2Se3 to obtain elements of Raman tensor for understanding strength of polarization along different crystallographic orientations. Intensity variation in polar plots corresponding to Eg1 -37 cm-1, A11g -71 cm-1, Eg2 -130 cm-1, and A21g -173 cm-1 suggests higher differential polarizability along the bc plane. The polar plots and elements of Raman tensor provide evidence of fundamental electron-phonon (e-ph) and anisotropic light-matter interactions in Bi2Se3.