Disorder suppression and tunable localization in ultrathin SrIrO3 films via SrTiO3 capping

(STO) capping layer suppresses localization in both types. The critical thickness for the metal-insulator transition decreases to below 3 u.c. for SIO_i and to 2 u.c. for SIO_m. Structural analysis suggests that the STO capping mitigates intrinsic disorder by inducing lattice relaxation in the ultrathin films. This approach offers a pathway to control electronic phases in correlated oxide heterostructures via interface engineering.