Ultra-high phase-locked harmonic generation from magnetic transversal confinement of electrons Luis Plaja, Rodrigo Martín-Hernández, Hongtao Hu, Andrius Baltuska and Carlos Hernández-García EPJ Web Conf., 287 (2023) 08009 Published online: 18 October 2023 DOI: 10.1051/epjconf/202328708009