Physics Colloquium with Edoardo Baldini

Abstract: Understanding how collective quantum behavior emerges and evolves in materials is a central challenge in modern physics. In quantum materials, interactions among charge, spin, orbital, and lattice degrees of freedom give rise to rich phases that are often difficult to probe selectively and control using conventional approaches.  

In this talk, I will present a research program that integrates the discovery of new quantum phases, the direct measurement of microscopic interactions, and the coherent control of collective modes. Using nonlinear optical techniques based on ultrashort laser pulses, we access symmetry, interactions, and dynamics in strongly correlated systems with high selectivity in time, energy, and polarization.  

I will illustrate this approach through three case studies in magnetic quantum materials. First, I will show how reduced dimensionality leads to unconventional ordering phenomena in atomically thin magnets. Second, I will demonstrate how ultrafast, symmetry-resolved spectroscopy enables the direct quantification of interactions underlying exotic collective excitations. Third, I will show how tailored driving of collective modes can generate hybrid nonlinear responses with mixed spin–orbital character that do not exist in equilibrium.  

I will conclude with an outlook on how these approaches can uncover new fundamental aspects of quantum materials and enable their use as functional platforms for sensing, information processing, and energy-efficient technologies.