Thin films of the correlated transition-metal oxide LaNiO3 undergo a metal-insulator transition when their thickness is reduced to a few unit cells. Here, we use angle-resolved photoemission spectroscopy to study the evolution of the electronic structure across this transition in a series of epitaxial LaNiO3 films of thicknesses ranging from 19 to 2 u.c. grown in situ by RF magnetron sputtering. Our data show a strong reduction of the electronic mean free path as the thickness is reduced below 5 u.c. This prevents the system from becoming electronically two-dimensional, as confirmed by the largely unchanged Fermi surface seen in our experiments. In the insulating state we observe a strong suppression of the coherent quasiparticle peak but no clear gap. These features resemble previous observations of the insulating state of NdNiO3.
@article{arxiv.2002.02276,
title = {A laser-ARPES study of LaNiO3 thin films grown by sputter deposition},
author = {Edoardo Cappelli and Willem Tromp and Siobhan McKeown Walker and Anna Tamai and Marta Gibert and Felix Baumberger and Flavio Y. Bruno},
journal= {arXiv preprint arXiv:2002.02276},
year = {2020}
}