Publication: Strain-induced gyrotropic effects in ferroelectric BaTi⁢S3

W. Luo, A. Zabalo, G. Ren, G.-Y. Jung, M. Stengel, R. Mishra, J. Ravichandran, and L. Bellaiche, "Strain-induced gyrotropic effects in ferroelectric BaTiS₃," Phys. Rev. B 113, L100101 (2026). https://doi.org/10.1103/zk45-6lb2

Abstract

We explore gyrotropic effects in the BaTi⁢S3 system, a quasi-one-dimensional crystal that exhibits giant optical anisotropy [S. Niu et al., Nat. Photon. 12, 392 (2018); B. Zhao et al., Chem. Mater. 34, 5680 (2022)]. In the 𝑃⁢63⁢𝑐⁢𝑚 phase which is stable under room temperature, we predict two distinct strain-induced phase transitions: (i) a symmetry-lowering transition from the 𝑃⁢63⁢𝑐⁢𝑚 to chiral 𝑃⁢63 phase under tensile strain (>3.0%), which enhances natural optical activity (NOA) and enables electric-field-switchable optical rotation; and an isostructural insulator-to-polar semimetal transition under compressive strain (≤−3%), which activates the nonlinear anomalous Hall effect and exhibits a strain-induced sign reversal. The low-temperature 𝑃⁢21 phase also transforms into a 𝑃⁢21⁢21⁢21 phase under enough compressive strains with such phase transition exhibiting a large NOA. All these results highlight BaTi⁢S3 as a viable candidate for ferroelectrics, chiral and optical devices with strain enhanced or activated gyrotropic properties.