Electronic correlation effects generate many fascinating properties in 3d transition metal oxides which hold great promise for future novel electronic functionalities. The Mott insulator to metal transitions as a function of band width or band filling may e.g. be harnessed in a Mott transistor. To utilize the metal-insulator transitions in devices, the understanding and control of these effects has yet to be improved.
It has been demonstrated that thin LaTiO₃ films are a promising channel material in future Mottronic devices [1]. Here we study the electronic structure across the band-filling induced phase transition in LaTiO₃ using angle-resolved photoemission spectroscopy as well as complementary transport experiments. The LaTiO₃ films are tuned by excess oxygen doping across the line of the band-filling controlled Mott transition, which allows us to derive the correlation between the band filling and the band mass.

[1] P. Scheiderer, M.Schmitt, J. Gabel, M. Zapf, M. Stübinger, P.Schütz, L. Dudy, C. Schlueter, T.-L. Lee, M.Sing, and R. Claessen, Adv. Mater. 30, 1706708 (2018)