\textit{in situ} studied correlated oxide LaNiO$_{3}$ ultra thin film by angle resolved photoemission spectroscopy

Recently, $R$NiO$_{3}$ ($R$: rare earth) attracted increasing attention due to the possible realization of the electronic band structure similar to the high-temperature superconductor cuprates. Among them, LaNiO$_{3}$ based heterostructures have shown various fascinating physical properties such as dimensionality controlled electronic phase transitions. Theoretical works on confined LaNiO$_{3}$ through heterostructuring predicted cuprate-like band structure and magnetic properties. Here, we reports \textit{in-situ} angle resolved photoemission spectroscopy results on the LaNiO$_{3}$ films grown by pulsed laser deposition method. We carefully controlled the thickness of LaNiO$_{3}$ films from one to 30 unit cells and measured the thickness dependent band dispersions. First, we will discuss the strong electronic correlation effect in bulk-like band structure of thick LaNiO$_{3}$ films comparing to the previously reported LDA+DMFT calculation. Moreover, we will discuss the thickness dependent band structure. As decreasing the film thickness, we observed the charge redistribution of two Ni $e_{g}$ orbitals at the Fermi surface. The origins of thickness dependent electronic structure will be discussed.