Angle-resolved photoemission spectroscopy (ARPES) in infinite-layer nickelates

The recent discovery of superconductivity in the family of hole-doped infinite-layer (IL) nickelates (Nd1-xSrxNiO2, x=dopant concentration) has spurred an entirely new field within the oxide community. Although other compounds of the same family have showed superconductivity, there are still many difficulties to reproduce the results among research groups. The complicated synthesis method consisting in a redox reduction by ex situ annealing the parent perovskite phase in the presence of CaH2, results in superconducting IL samples that are not coherent, present many impurities, and a degraded surface quality. Samples obtained in this form are not suitable for surface-sensitive experiments. The development over the last year of an alternative in-situ method to obtain the infinite-layer phase by Al deposition on top of the perovskite 3D parent compound in an UHV environment opens up the possibility of performing such surface sensitive experiments. We propose to investigate the electronic structure of the superconducting infinite-layer nickelates phase using angle resolved photoemission spectroscopy (ARPES) obtained by this novel synthesis method. Our main aim will be to capture for the first time the reduction of dimensionality of the electronic band structure from 3D to 2D character due to the transformation from the parent perovskite 3D phase into the IL phase. This will allow us to gain insight into the electronic band structure of the IL superconducting phase of nickelates which remains unexplored so far.