Figure S1-S5;Table S1-S2

Figure S1. Schematic diagram of (a) LaInO3/BaSnO3, (b) BaTiO3/LaInO3/BaSnO3 and (c) LaInO3/BaSnO3/BaTiO3 HS systems. Table S1 The coordinates of each ion along the z-axis, the relative displacement between the In3+/La3+ cations and O2- anions of the LaInO3 film in LaInO3/BaSnO3, BaTiO3/LaInO3/BaSnO3 and LaInO3/BaSnO3/BaTiO3 HS systems, respectively. Figure S2. (a) The layer-resolved partial DOS and (b) the crystal structure of fully-relaxed (BaTiO3)2/LaInO3/BaSnO3 system. (c) The enlarged view of the PDOS for IF-I, IF-Ⅱ and IF-Ⅲ layers, respectively. Figure S3. (a) The layer-resolved partial DOS and (b) the crystal structure of fully-relaxed (BaTiO3)5/LaInO3/BaSnO3 system. (c) The enlarged view of the PDOS for IF-I, IF-Ⅱ and IF-Ⅲ layers, respectively. Table S2. The interfacial charge density of the (BaTiO3)m/LaInO3/BaSnO3 system with different thicknesses of the BaTiO3 film. Figure S4. (a) The layer-resolved partial DOS and (b) the crystal structure of the partial-relaxed BaTiO3(-0.003)/LaInO3/BaSnO3 system where the atomic fraction coordinates distance between Ti4+/Ba2+cation and O2- anion in the BaTiO3 film equals -0.003. (c) The enlarged view of the PDOS for IF-Ⅰ, IF-Ⅱ and IF-Ⅲ layers, respectively. Figure S5. (a) The layer-resolved partial DOS and (b) the crystal structure of the partial-relaxed BaTiO3(+0.001)/LaInO3/BaSnO3 system, where the atomic fraction coordinates distance between Ti4+/Ba2+cation and O2- anion in the BaTiO3 film equals +0.001. (c) The enlarged view of the PDOS for the IF-Ⅰ, IF-Ⅱ and IF-Ⅲ layers, respectively.