Time-based method helps probe quantum material transitions

Researchers from Massachusetts Institute of Technology, Shanghai Jiao Tong University, Stanford, Harvard, and ETH Zürich have established a new time-domain method for investigating competing charge density waves within the rare-earth tritelluride ErTe3. The work reveals that this material hosts two distinct electron arrangement patterns competing for dominance, a phenomenon challenging existing understanding of phase transitions. By analyzing the recovery dynamics of these waves following light excitation, the team uncovered a novel nucleation and growth mechanism driving the subdominant charge density wave, a process previously unexplained by conventional models. This research introduces a non-equilibrium framework for understanding phase competition in quantum materials. Rare-earth tritelluride, specifically ErTe₃, presents a unique challenge to condensed matter physics due to the coexistence of competing charge density waves within its structure. Unlike many materials where a single dominant CDW phase arises from established mechanisms like Fermi surface nesting or electron-phonon interactions, the formation of the secondary CDW in ErTe₃ has remained poorly understood and defies conventional explanations. Researchers combined time- and angle-resolved photoemission spectroscopy with time-dependent Ginzburg-Landau theory to create a method for examining…