thin films*

Rare-earth titanate YTiO₃ is a Mott insulator whose electronic structure description has been quite challenging to density functional theory (DFT) calculations within standard (semi)local approximations to the exchange-correlation term. The reported onset of optical absorption in YTiO₃ is ~0.6 eV while the calculated Mott-Hubbard gap using hybrid DFT is ~2 eV. Combining experiments on hybrid molecular beam epitaxy (MBE) grown YTiO₃ heterostructures with DFT calculations we investigated the electronic and transport properties of YTiO₃. We test the performance of the meta-GGA SCAN functional in the description of the electronic structure of YTiO₃, comparing the results of hybrid functional and photoemission measurements. We also study the formation, stability and migration of small hole polarons in YTiO₃, and compare our findings with the measurements of the Seebeck coefficient and temperature-dependent resistivity. We also carry out a detailed analysis of the effects of the TiO₆ octahedral tilt and rotations, and lattice distortions on the Mott-Hubbard gap.