Quantum interference directed chiral Raman scattering in two-dimensional enantiomers

Raman scattering spectroscopy is an accurate tool for characterizing lattice structure and probing electron–photon and electron–phonon interactions. In the quantum picture, electrons at ground states are excited to intermediate energy levels by photons at different k-points in the Brillouin zone, then couple to phonons and emit photons with shifted energies. Elementary Raman processes via multiple pathways can interfere, yielding intriguing scattering effects. Here we report that quantum interference leads to significant chiral Raman response in monolayer transition metal dichalcogenides with triclinic symmetry. Large circular intensity differences observed for monolayer rhenium dichalcogenides originate from inter-k interference of Raman scattering excited by circularly polarized light with opposite helicities. Our results reveal chiral Raman spectra as a new manifestation of quantum interference in Raman scattering and may inspire induction of chiral optical responses in other materials.

Shishu Zhang, Jianqi Huang, Yue Yu, Shanshan Wang, Teng Yang, Zhidong Zhang, Lianming Tong, Jin Zhang