Shot noise in a metal close to Mott transition

TL;DR

This study investigates shot noise in nanoscale SrIrO$_3$ junctions, revealing suppressed noise indicative of collective electron hopping near a Mott transition, thus providing new insights into its non-Fermi liquid state.

Contribution

It demonstrates that shot noise suppression in SrIrO$_3$ indicates collective hopping conduction, advancing understanding of electron correlations near the Mott transition.

Findings

Shot noise is strongly suppressed in SrIrO$_3$ junctions.

Conduction is mediated by collective hopping of electrons.

Results suggest a non-Fermi liquid state near the Mott transition.

Abstract

SrIrO$_3$ is a metallic complex oxide with unusual electronic and magnetic properties believed to originate from electron correlations due to its proximity to Mott metal-insulator transition. However, the nature of its electronic state and the mechanism of metallic conduction remain poorly understood. We demonstrate that shot noise produced by nanoscale SrIrO$_3$ junctions is strongly suppressed, inconsistent with diffusive quasiparticle transport. Analysis of thermal effects and scaling with the junction length reveals that conduction is mediated by collective hopping of electrons almost localized by correlations. Our results provide insight into the non-Fermi liquid state close to Mott transition, and advance shot noise measurements as a powerful technique for the studies of quantum materials.