Changing the properties of materials on demand is crucial both for understanding the conditions which allow for the appearance of emergent order and for generating new functionalities. Using laser light for this purpose is a particularly interesting approach: It provides control on femtosecond time scales, and may lead to the creation of non-equilibrium steady states without static equivalents. Strongly driven materials essentially become light-matter hybrids, where photons can determine the the symmetries and the collective modes of the system. Progress in this research direction is benefitting from current breakthroughs in experimental techniques for generating long-wavelength laser pulses and extending new observables to the ultrafast regime, but also from theoretical advancements in the simulation of quantum many-body systems. I will introduce some of the key concepts and techniques for creating such “dynamic quantum materials,” which may differ from their static counterparts in their band topology or magnetic order. I will in particular focus on recent experiments showing light-induced magnetic flux expulsion from a laser-driven cuprate, which persists up to 300K. This measurement was facilitated using an ultrafast magnetometry technique which opens up exciting new experiments including new insights on the effects of dynamically chiral phonons, the dynamics of flux quantization in superconductors, and the possibility of probing a Floquet-engineered phase transition in quantum magnets. It also enables a novel type of ultrafast magneto-spectroscopy, which was already applied to a ferrimagnetic thin film, but could also be of interest to studying non-magnetic 2D materials.
Please register at our doodle if you want to join for pizza!
Location: Stuckelberg, Ecole de Physique
Time: Tuesday 5 November 2024, 12:30 for pizza, 13:00 start discussion