Optical properties of LaNiO3 films tuned from compressive to tensile strain

Abstract

Materials with strong electronic correlations host remarkable -- and technologically relevant -- phenomena such as magnetism, superconductivity and metal-insulator transitions. Harnessing and controlling these effects is a major challenge, on which key advances are being made through lattice and strain engineering in thin films and heterostructures, leveraging the complex interplay between electronic and structural degrees of freedom. Here we show that the electronic structure of LaNiO3 can be tuned by means of lattice engineering. We use different substrates to induce compressive and tensile biaxial epitaxial strain in LaNiO3 thin films. Our measurements reveal systematic changes of the optical spectrum as a function of strain and, notably, an increase of the low-frequency free carrier weight as tensile strain is applied. Using density functional theory (DFT) calculations, we show that this apparently counter-intuitive effect is due to a change of orientation of the oxygen octahedra.The calculations also reveal drastic changes of the electronic structure under strain, associated with a Fermi surface Lifshitz transition. We provide an online applet to explore these effects. The experimental value of integrated spectral weight below 2 eV is significantly (up to a factor of 3) smaller than the DFT results, indicating a transfer of spectral weight from the infrared to energies above 2 eV. The suppression of the free carrier weight and the transfer of spectral weight to high energies together indicate a correlation-induced band narrowing and free carrier mass enhancement due to electronic correlations. Our findings provide a promising avenue for the tuning and control of quantum materials employing lattice engineering.

12 pages, 11 figures

References in corpus (9)

• Electrodynamics of Correlated Electron Materials
• Orbital order and possible superconductivity in LaNiO3/LaMO3 superlattices
• Plane-wave based electronic structure calculations for correlated materials using dynamical mean-field theory and projected local orbitals
• Low-energy description of the metal-insulator transition in the rare-earth nickelates
• Evolution of the optical spectrum with doping in iron pnictides Ba(Fe1-xCox)2As2
• Non-Drude universal scaling laws for the optical response of local Fermi liquids
• Orbital Polarization in Strained LaNiO${}_3$: Structural Distortions and Correlation Effects
• Latent Instabilities in Metallic LaNiO3 Films by Strain Control of Fermi-Surface Topology
• Renormalization of effective interactions in a negative charge-transfer insulator

Cited by in corpus (2)

• Sensitive dependence of pairing symmetry on Ni-$e_g$ crystal field splitting in the nickelate superconductor La${}_3$Ni${}_2$O${}_7$
• Interplay between electron correlations, magnetic state, and structural confinement in LaNiO3 ultrathin films