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.