Event

Dynamics and control of quantum materials using light has emerged as a frontier research area.  There are numerous possibilities to investigate including photoinduced metastability, creating non-equilibrium states with emergent properties, or impulsively driving an order parameter to investigate the nonlinear “optical” response which can encode properties not evident with linear optical probes. Terahertz spectroscopy is a particularly useful probe of low energy electrodynamics in quantum materials in both the static and dynamic limits. Following a brief introduction to this area of research, I will present concrete examples from my research group. This includes: (i) Gentle photoexcitation of La2-xBaxCuO4 resulting in a collapse of charge order with the development of incipient superconducting signatures above the equilibrium superconducting transition temperature. (ii) Gentle photoexcitation of the putative excitonic insulator Ta2NiSe5 resulting in stimulated nonlinear parametric generation that serves as a reporter of the excitonic condensate and its coupling to phonons.