Gaps and pseudo-gaps at the Mott quantum Critical point in the perovskite rare earth nickelates

Abstract

We report on tunneling measurements that reveal for the first time the evolution of the quasi-particle state density across the bandwidth controlled Mott metal to insulator transition in the rare earth perovskite nickelates. In this, a canonical class of transition metal oxides, we study in particular two materials close to the T=0 metal-insulator transition: NdNiO3 , an antiferromagnetic insulator, and LaNiO3, a correlated metal. We measure a sharp gap in NdNiO3, which has an insulating ground state, of ~ 30 meV. Remarkably, metallic LaNiO3 exhibits a pseudogap of the same order that presages the metal insulator transition. The smallness of both the gap and pseudogap suggests they arise from a common origin: proximity to a quantum critical point at or near the T=0 metal-insulator transition. It also supports theoretical models of the quantum phase transition in terms of spin and charge instabilities of an itinerant Fermi surface.

arXiv comment5 figures, 22 pages

References in corpus (13)

• Calculations of Hubbard U from first-principles
• Metal-insulator transition in ultrathin LaNiO3 films
• Site-selective Mott transition in rare earth nickelates
• Nonmagnetic Insulating States near the Mott Transitions on Lattices with Geometrical Frustration and Implications for $\kappa$-(ET)${}_2$Cu${}_2(CN{)}_3$
• Theory of a continuous Mott transition in two dimensions
• Mott Transition, Antiferromagnetism, and d-wave Superconductivity in Two-Dimensional Organic Conductors
• Origins of bad metal conductivity and the insulator-metal transition in the rare-earth nickelates
• Strain-mediated metal-insulator transition in epitaxial ultra-thin films of NdNiO3
• Theory of the magnetic and metal-insulator transitions in RNiO3 bulk and layered structures
• Metal-insulator transition in a two-band model for the perovskite nickelates
• Fermi surfaces, electron-hole asymmetry and correlation kink in a three-dimensional Fermi liquid LaNiO${}_3$
• Structural phase transitions in epitaxial perovskite films
• Unusual temperature dependence of the spectral weight near the Fermi level of NdNiO3 thin films

Cited by in corpus (1)

• Observation and Structural Control of Charge-Density-Waves resonating with Terahertz Frequencies in NdNiO3