The charge-density-wave (CDW) phase of layered dichalcogenide 1T-TiSe2 has been a subject of intense scrutiny since its discovery in the 1970s. In thermal equilibrium, this phase reportedly features excitonic condensation, chiral CDW, 2D CDW in a monolayer, and superconductivity upon doping — many of which are discovered here at Urbana-Champaign.
Leveraging some of these equilibrium properties, I will show how the nonequilibrium CDW state in 1T-TiSe2 helps answer key questions in our recent pursuit of materials engineering by ultrashort laser pulses. The first part of my talk will aim to answer how dimensionality and strong correlations together govern the pathway of a photoinduced transition . In the second part, we will explore the fundamental limit on how fast topological defects can emerge in solids .
 Nat. Commun. 13, 963 (2022)
 Nat. Phys., in press (2023). arXiv:2211.05748