2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/19628By measuring the angles at which the Landau levels overlap in tilted magnetic fields (the coincidence method), we determine the splitting of the conduction-band valleys in high-mobility two-dimensional (2D) electrons confined to AlAs quantum wells. The data reveal that, while the valleys are nearly degenerate in the absence of magnetic field, they split as a function of perpendicular magnetic field. The splitting appears to depend primarily on the magnitude of the perpendicular component of the magnetic field, suggesting electron-electron interaction as its origin.Revtex4: 4 pages, 4 figures. Submitted for publicationStrongly Correlated ElectronsMesoscale and Nanoscale Physicstext