Light-driven symmetry control of crystalline materials

The relationship between structure, symmetry, and function is central to condensed matter physics, dictating physical properties, revealing hidden order, and guiding the design of new phenomena. But many solids are limited to a few structural phases by their underlying chemistry, constraining the range of accessible properties. Advances in mid- and far-infrared laser sources now provide a route to dynamically control crystal structures on sub-picosecond timescales. In this talk, I will present our theoretical work on driving symmetry and structural changes via direct excitation of infrared-active phonons – enabling access to non-equilibrium phases and emergent symmetries.