Employing nonlinear, time-resolved terahertz spectroscopy to study condensate dynamics on Ta2NiSe5—a narrow-bandgap semiconductor and putative excitonic insulator—the authors reveal enhanced terahertz reflectivity upon photoexcitation and condensation-like temperature dependence below the structural transition critical temperature.
- Sheikh Rubaiat Ul Haque
- Marios H. Michael
- Richard D. Averitt