Twisting Light and Spin in Chiral Halide Perovskites

Chiral hybrid halide perovskites offer a unique platform where structural chirality, lattice dynamics, and spin–orbit coupling converge to generate rich optical and spin-dependent phenomena. Their soft lattices and flexible organic–inorganic frameworks allow strong responses to atomic motion, making them ideal for exploring how lattice dynamics influence light–matter and spin interactions.

Using first-principles and machine-learning–accelerated simulations, we investigate the lattice dynamics, optical activity, and spin textures of two-dimensional chiral lead-halide perovskites. We identify vibrational modes with chiral character—chiral phonons—that couple to excitonic and spin states, modulating both circular dichroism and spin polarization. Temperature-dependent structural fluctuations play a key role in tuning these chiroptical and spin-resolved properties. Together, these results provide a microscopic understanding of how chirality manifests across the lattice, optical, and spin degrees of freedom. Building on this foundation, we outline a future direction linking these effects through electron–phonon coupling, offering new perspectives on the dynamic origins of chiral-induced spin selectivity (CISS) in hybrid perovskites.