Exploring non-equilibrium ferroelectric phases via twisted light–matter interaction

The interaction of twisted light carrying orbital angular momentum (OAM) with matter has gained attention for its applications in nanotechnology, quantum optics, and condensed matter physics. Twisted light can enhance absorption, generate photocurrents, and manipulate excitons and quasiparticles. We show that opto-mechanical and opto-electronic transduction is possible using twisted Laguerre-Gaussian (LG) modes, where OAM is quantized as <i>&ell;&hstrok;</i> per photon. Using Bragg coherent diffractive imaging and Raman spectroscopy, we demonstrate that twisted ultraviolet LG light can reversibly manipulate atomic distortions and ferroelectric polarization in quasi-2D CsBiNb₂O₇, a Rashba ferroelectric perovskite with tunable spin polarization. Twisted light may also control spin textures such as the persistent spin helix, which preserves spin coherence. These findings pave new pathways for optical control of ferroelectric and spintronic properties in complex materials.