Confinement-induced metal-to-insulator transition in strained LaNiO${}_3$/LaAlO${}_3$ superlattices

Abstract

Using density functional theory calculations including a Hubbard $U$ term we explore the effect of strain and confinement on the electronic ground state of superlattices containing the band insulator LaAlO${}_3$ and the correlated metal LaNiO${}_3$. Besides a suppression of holes at the apical oxygen, a central feature is the asymmetric response to strain in single unit cell superlattices: For tensile strain a band gap opens due to charge disproportionation at the Ni sites with two distinct magnetic moments of 1.45${\mu }_{\mathrm{B}}$ and 0.71${\mu }_{\mathrm{B}}$. Under compressive stain, charge disproportionation is nearly quenched and the band gap collapses due to overlap of $d_{3z^2-r^2}$ bands through a semimetallic state. This asymmetry in the electronic behavior is associated with the difference in octahedral distortions and rotations under tensile and compressive strain. The ligand hole density and the metallic state are quickly restored with increasing thickness of the (LaAlO${}_3$)${}_n$/(LaNiO${}_3$)${}_n$ superlattice from $n=1$ to $n=3$.

7 pages, 10 Figures

References in corpus (5)

• Orbital order and possible superconductivity in LaNiO3/LaMO3 superlattices
• Role of magnetic and orbital ordering at the metal-insulator transition in NdNiO3
• Bulk magnetic order in a two dimensional Ni1+/Ni2+ (d9/d8) nickelate, isoelectronic with superconducting cuprates
• Chemical control of orbital polarization in artificially structured transition-metal oxides: La2NiXO6 (X=B, Al, Ga, In) from first principles
• Onset of metallic behavior in strained (LaNiO3)n/(SrMnO3)2 superlattices

Cited by in corpus (8)

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• Confinement-driven transitions between topological and Mott phases in (LaNiO3)${}_N$/(LaAlO3)${}_M$(111) superlattices
• Orbital Polarization in Strained LaNiO${}_3$: Structural Distortions and Correlation Effects
• Design of $n$- and $p$-type oxide thermoelectrics in LaNiO${}_3$/SrTiO${}_3(001)$ superlattices exploiting interface polarity
• Ordering and multiple phase transitions in ultra-thin nickelate superlattices
• Electronic and magnetic structures of hole doped trilayer La(4-x)Sr(x)Ni3O8 from first principles calculations