Year: 2026
Type: article
Abstract: Raman optical activity (ROA), the dependence of Raman intensity on the circular polarization of incident and scattered light, has traditionally been observed in chiral molecules and magnetic materials, where inversion or time-reversal symmetry is broken. Here we demonstrate that ROA can also arise in a centrosymmetric and nonmagnetic ferroaxial crystal. Using circularly polarized Raman spectroscopy on single-crystalline NiTiO_{3}, we observed a pronounced ROA signal in the cross-circular polarization configurations, which correlates with the ferroaxial domain structure. Our symmetry analysis, first-principles calculations of phonons, and tight-binding model calculations reveal that the natural ROA originates from the ferroaxial order and persists even within the electric dipole approximation. These results establish ROA as a powerful probe of ferroaxial order in centrosymmetric systems.
Source: Physical Review Letters
DOI: 10.1103/wrv8-4f7k
Authors: Gakuto Kusuno, Takeshi Hayashida, Takayuki Nagai, Hikaru Watanabe, Rikuto Oiwa, Tsuyoshi Kimura, Takuya Satoh
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: G1987219981, 高速スピンデバイスに向けたテラヘルツ光電インターフェースの創出, G4988087856, G5164354190, 磁気構造探索と統合的物性スクリーニングによる機能反強磁性体設計, G564268175, Exploration of novel materials' properties based on multiferroic conversion, G5773010482, G6054978281, G6099920409, Theoretical study of photo-induced control and emergent itinerant responses in electrically-active antiferromagnets, G6718509927, G6816641397, G7135277432, G7879866177, Novel Magnetization Control via Light and Chiral Phonons, G940152018
OpenAlex ID: W4416048541