Quantum Matter Seminar

A key frontier of modern condensed matter is to harness light–matter interaction to coherently engineer quantum states in materials. Under optical driving, quantum materials exhibit emergent many-body phenomena, from ultrafast switching to dynamical quantum states without equilibrium analogs. Progress hinges on using light to both uncover new nonequilibrium states and devise strategies to stabilize them far beyond the duration of the drive.

One-dimensional Mott insulators are particularly compelling platforms for these goals. Electron fractionalization produces highly entangled ground states that are exceptionally responsive to optical perturbations, and theory predicts exotic ordering phenomena upon photoexcitation. In this talk, I will show how ultrafast X-ray spectroscopy provides a direct, microscopic view of these dynamics by resolving charge and spin responses of optically driven phases. I will discuss our observation of a photoinduced Tomonaga–Luttinger liquid state in the one-dimensional cuprate chain Sr2CuO3. I will then show how nonequilibrium states can be stabilized for nanosecond timescales by leveraging symmetry constraints in the parent ladder compound Sr14Cu24O41.