4 research outputs found
Many-body electronic structure of layered nickelates
The recent observation of superconductivity in an infinite-layer and
quintuple-layer nickelate within the same NiO series
( = rare-earth, , with indicating the number of NiO
layers along the -axis), unlocks their potential to embody a whole family of
unconventional superconductors. Here, we systematically investigate the
many-body electronic structure of the layered nickelates (with )
within a density-functional theory plus dynamical mean-field theory framework
and contrast it with that of the known superconducting members of the series
and with the cuprates. We find that many features of the electronic structure
are common to the entire nickelate series, namely, strongly correlated
Ni- orbitals that dominate the low-energy physics, mixed
Mott-Hubbard/charge-transfer characteristics, and () orbitals acting as
charge reservoirs. Interestingly, we uncover that the electronic structure of
the layered nickelates is highly tunable as the dimensionality changes from
quasi-two-dimensional to three-dimensional as .
Specifically, we identify the tunable electronic features to be: the
charge-transfer energy, presence of states around the Fermi level, and
the strength of electronic correlations.Comment: 8 pages, 7 figure
Antiferromagnetic metal phase in an electron-doped rare-earth nickelate
Long viewed as passive elements, antiferromagnetic materials have emerged as
promising candidates for spintronic devices due to their insensitivity to
external fields and potential for high-speed switching. Recent work exploiting
spin and orbital effects has identified ways to electrically control and probe
the spins in metallic antiferromagnets, especially in noncollinear or
noncentrosymmetric spin structures. The rare earth nickelate NdNiO3 is known to
be a noncollinear antiferromagnet where the onset of antiferromagnetic ordering
is concomitant with a transition to an insulating state. Here, we find that for
low electron doping, the magnetic order on the nickel site is preserved while
electronically a new metallic phase is induced. We show that this metallic
phase has a Fermi surface that is mostly gapped by an electronic reconstruction
driven by the bond disproportionation. Furthermore, we demonstrate the ability
to write to and read from the spin structure via a large zero-field planar Hall
effect. Our results expand the already rich phase diagram of the rare-earth
nickelates and may enable spintronics applications in this family of correlated
oxides.Comment: 25 pages, 4 figure
Recommended from our members
Limits to the strain engineering of layered square-planar nickelate thin films
The layered square-planar nickelates, Ndn+1NinO2n+2, are an appealing system to tune the electronic properties of square-planar nickelates via dimensionality; indeed, superconductivity was recently observed in Nd6Ni5O12 thin films. Here, we investigate the role of epitaxial strain in the competing requirements for the synthesis of the n = 3 Ruddlesden-Popper compound, Nd4Ni3O10, and subsequent reduction to the square-planar phase, Nd4Ni3O8. We synthesize our highest quality Nd4Ni3O10 films under compressive strain on LaAlO3 (001), while Nd4Ni3O10 on NdGaO3 (110) exhibits tensile strain-induced rock salt faults but retains bulk-like transport properties. A high density of extended defects forms in Nd4Ni3O10 on SrTiO3 (001). Films reduced on LaAlO3 become insulating and form compressive strain-induced c-axis canting defects, while Nd4Ni3O8 films on NdGaO3 are metallic. This work provides a pathway to the synthesis of Ndn+1NinO2n+2 thin films and sets limits on the ability to strain engineer these compounds via epitaxy