Nanostructure Investigations of Nonlinear Differential Conductance in NdNiO$_3$ Thin Films

TL;DR

This study investigates the nonlinear differential conductance in NdNiO$_3$ thin films, revealing a transition to non-Ohmic behavior below the metal-insulator transition, consistent with gap formation in the Fermi surface and Landau-Zener breakdown at low temperatures.

Contribution

It provides new insights into the nonlinear transport mechanisms and gap evolution in NdNiO$_3$ thin films across the metal-insulator transition.

Findings

Nonlinear conduction emerges below the transition temperature.

Transport behavior aligns with Landau-Zener breakdown at low temperatures.

Evidence of gap formation in the Fermi surface of NdNiO$_3$.

Abstract

Transport measurements on thin films of NdNiO$_3$ reveal a crossover to a regime of pronounced nonlinear conduction below the well-known metal-insulator transition temperature. The evolution of the transport properties at temperatures well below this transition appears consistent with a gradual formation of a gap in the hole-like Fermi surface of this strongly correlated system. As $T$ is decreased below the nominal transition temperature, transport becomes increasily non-Ohmic, with a model of Landau-Zener breakdown becoming most suited for describing $I(V)$ characteristics as the temperature approaches 2~K.