Hot electron transport in a strongly correlated transition metal oxide

TL;DR

This study investigates hot-electron transport in a strongly correlated oxide heterointerface, revealing the attenuation length and scattering mechanisms, with implications for oxide-electronics and local transport visualization.

Contribution

It provides the first measurement of hot-electron attenuation length in LSMO and analyzes the dominant scattering processes affecting electron transport.

Findings

Attenuation length is approximately 1.48 u.c. at -1.9 V and 2.02 u.c.. at -1.3 V.

Electron-electron and polaron scattering dominate the transport.

Local electron transmission varies at terraces and step-edges.

Abstract

Oxide heterointerfaces are ideal for investigating strong correlation effects to electron transport, relevant for oxide-electronics. Using hot-electrons, we probe electron transport perpendicular to the La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ (LSMO)- Nb-doped SrTiO$_3$ (Nb:STO) interface and find the characteristic hot-electron attenuation length in LSMO to be 1.48 $\pm$ 0.10 unit cells (u.c.) at -1.9 V, increasing to 2.02 $\pm$ 0.16 u.c. at -1.3 V at room temperature. Theoretical analysis of this energy dispersion reveals the dominance of electron-electron and polaron scattering. Direct visualization of the local electron transport shows different transmission at the terraces and at the step-edges.