Probing momentum-resolved electronic structure of buried artificial graphenelike Mott crystal NdNiO3 [111] with soft x-ray angle-resolved photoemission
ORAL
Abstract
Transition metal oxides (TMO) exhibit a wide variety of potentially advantageous strongly-correlated electronic phenomena such as metal-insulator transitions, high-Tc superconductivity, half-metallicity, etc. Until now, however, most of the work has been focused on synthesizing and investigating systems that are grown along the [001] pseudocubic direction. Here we utilize soft x-ray angle-resolved photoemission spectroscopy to investigate the momentum-resolved valence-band electronic structure of artificial graphenelike Mott crystal NdNiO3 grown along the [111] direction. Our measurements reveal broken six-fold symmetry of the Ni 3d eg states hosted on a buckled honeycomb lattice. This engineered electronic structure is unique to the ultrathin (2 u.c.) quazi-2D crystal, and cannot be realized either in the bulk or in the thin-film Nickelate grown along the conventional [001] direction. Our findings open the door for engineering novel polarized Mott-electronic ground states in rare-earth Nickelates, as well as other strongly-correlated transition-metal oxides.
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