Integer quantum Hall effect and enhanced g factor in quantum-confined Cd3As2 films

We investigate the integer quantum Hall effect in Cd3As2 thin films under conditions of strong to moderate quantum confinement (thicknesses of 10, 12, and 15 nm). In all the films, we observe the integer quantum Hall effect in the spin-polarized lowest Landau level (filling factor ν=1) and at spin-degenerate higher index Landau levels with even filling factors (ν=2,4,6). With increasing quantum confinement, we also observe a lifting of the Landau-level spin degeneracy at ν=3, manifest as the emergence of an anomaly in the longitudinal and Hall resistivities. Tight-binding calculations show that the enhanced g factor likely arises from a combination of quantum confinement and corrections from nearby subbands.