The in-plane anisotropy of topological semimetal Nb₃SiTe₆ investigated by angle-resolved polarized Raman spectroscopy

The in-plane anisotropy of the layered topological semimetal Nb₃SiTe₆, owing to its unique lattice structure and nontrivial electronic states, may play an important role in low-power, multifunctional optoelectronic devices by regulating anisotropy, and provide an ideal research platform for exploring quantum phenomena such as chiral anomaly and quantum Hall effect. In the above-mentioned research related to material anisotropy, it is necessary to determine the crystallographic orientation of thin-layer samples. In this paper, we systematically studied the optical in-plane anisotropy of the layered topological semimetal Nb₃SiTe₆ via angle-resolved polarized Raman spectroscopy. The Raman intensities of the 13 Raman peaks show clear polarization dependence. Based on the lattice symmetry of multilayer Nb₃SiTe₆, we accurately distinguished the two Raman modes of Nb₃SiTe₆ and corresponding Raman peaks. In addition, we proposed a method for quickly, accurately, and nondestructively determining the crystallographic orientation of multilayer Nb₃SiTe₆ by polarized Raman spectroscopy. This work provides a crucial foundation for exploring potential applications of the anisotropy of Nb₃SiTe₆ in thermoelectric and optoelectronic fields.