Chiral optics without chiral matter

Abstract

Strong chiral light-matter interactions are conventionally believed to require structurally chiral materials. However, emerging evidence challenges this assumption, prompting a fundamental question: do chiral matters really matter in circularly polarized light (CPL) responses? While chiral structures favor circular dichroism generation in isotropic media, non-chiral systems with anisotropy can generate circular dichroism, and CPL can drive directional charge transport and spin-selective processes without structural chirality. By unifying these phenomena through fundamental light-matter interaction principles, recognizing that light carries both chiral and achiral components while matter exhibits diverse degrees of freedom such as charge, moment and angular momentum, we reveal a broader landscape of chiral optics. This perspective reconciles seemingly disparate findings and opens pathways to advanced technologies including high-performance CPL devices, ultrasensitive chiral sensors, and spin-selective photocatalysts, fundamentally expanding chiral optics beyond traditional structural constraints.