First experimental observation of zonal flows in the optimized stellarator Wendelstein 7-X - Carralero, D; Estrada, T; Garcia-Regana, J M; Sanchez, E; Windisch, T; Alonso, A; Maragkoudakis, E; Brandt, C; Brunner, K J; Gallego-Castillo, C; Kornejew, P; Parks, K; et al. (Physical Review Research, 2025)