Quantum confinement of Mott electrons in ultrathin LaNiO_{3}/LaAlO_{3} superlattices (original) (raw)
We investigate the electronic reconstruction in (LaNiO3)n/(LaAlO3)3 (n =3, 5 and 10) superlattices due to the quantum confinement (QC) by d.c. transport and resonant soft x-ray absorption spectroscopy. In proximity to the QC limit, a Mott-type transition from an itinerant electron behavior to a localized state is observed. The system exhibits tendency towards charge-order during the transition. ab initio cluster calculations are in good agreement with the absorption spectra, indicating that the apical ligand hole density is highly suppressed resulting in a strong modification of the electronic structure. At the dimensional crossover cellular dynamicalmean-field calculations support the emergence of a Mott insulator ground state in the heterostructured ultra-thin slab of LaNiO3.