Role of electron correlation and disorder on the electronic structure of layered nickelate (La${}_{0.5}$Sr${}_{0.5}$)${}_2$NiO${}_4$

Abstract

We investigate the role of electron correlation and disorder on the electronic structure of layered nickelate (La${}_{0.5}$Sr${}_{0.5}$)${}_2$NiO${}_4$ using core level and valence band photoemission spectroscopy in conjunction with density functional theory (DFT) and dynamical mean field theory (DMFT) calculations. Sr 3$d$ and La 4$d$ core level spectra exhibit multiple features associated with photoemission final state effects. An increase of unscreened features in the Sr 3$d$ and La 4$d$ core level spectra with lowering temperature suggests the reduction in density of states (DOS) at the Fermi level, $E_F$. Valence band spectra collected using different photon energies reveal finite intensity at $E_F$ and overall spectra are well captured by DFT+DMFT. Strong renormalization of partially filled $e_g$ bands in DFT+DMFT result indicates strong correlation in this system. Mass enhancement factor, $m^{\ast }/m_{\text{DFT}}\sim$ 3, agrees well with values obtained from specific heat measurements. High resolution spectra in the vicinity of $E_F$ show monotonically decreasing spectral intensity with lowering temperature, which evolves to exhibit a Fermi cut-off at low temperatures indicating metallic character in contrast to insulating transport, suggesting Anderson insulating state. $|E-E_F{|}^{1/2}$ dependence of the spectral DOS and square root temperature dependence of spectral DOS at $E_F$ evidences the role of disorder in the electronic structure of (La${}_{0.5}$Sr${}_{0.5}$)${}_2$NiO${}_4$.

arXiv commentTo appear in Physical Review Materials

References in corpus (17)

• Electronic Structure Calculations with Dynamical Mean-Field Theory: A Spectral Density Functional Approach
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Dynamical Mean-Field Theory within the Full-Potential Methods: Electronic structure of Ce-115 materials
• Electronic structure of the parent compound of superconducting infinite-layer nickelates
• Exact double-counting in combining the Dynamical Mean Field Theory and the Density Functional Theory
• Dynamical Mean Field Studies of Infinite Layer Nickelates: Physics Results and Methodological Implications
• Direct observation of dynamic charge stripes in La2-xSrxNiO4
• Critical test for Altshuler-Aronov theory: Evolution of the density of states singularity in double perovskite Sr${}_2$FeMoO${}_6$ with controlled disorder
• Neutron scattering study of spin ordering and stripe pinning in superconducting La${}_{1.93}$Sr${}_{0.07}$CuO${}_4$
• Evidence for Fluctuating Charge Stripes far above the Charge-Ordering Transition in La${}_{1.67}$ Sr${}_{0.33}$ NiO${}_4$
• Dimensional cross-over and charge order in half-doped Manganites and Cobaltites
• X-ray photoemission spectroscopy of La(0.67)Ca(0.33)MnO(3) films
• Assessing the correlated electronic structure of lanthanum nickelates
• Role of disorder and strong 5$d$ electron correlation in the electronic structure of Sr2TiIrO6
• LaBaNiO4: A Fermi glass
• Electronic structure of ternary palladates and effect of hole doping: A valence band photoemission spectroscopic study
• Revelation of Mott insulating state in layered honeycomb lattice Li${}_2$RuO${}_3$

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