Conduction of topologically-protected charged ferroelectric domain walls

TL;DR

This study demonstrates nanoscale conduction differences at ferroelectric domain walls in HoMnO3, revealing how charge and topology influence electrical properties, which advances understanding of ferroelectric semiconducting behavior.

Contribution

It provides the first detailed nanoscale conduction measurements at topologically protected ferroelectric domain walls in HoMnO3 using advanced microscopy techniques.

Findings

Negatively charged tail-to-tail walls show enhanced conduction at high forward bias.

Positively charged head-to-head walls exhibit suppressed conduction at high reverse bias.

Conductance spectra reveal bias-dependent conduction behavior related to domain wall charge.

Abstract

We report on the observation of nanoscale conduction at ferroelectric domain walls in hexagonal HoMnO3 protected by the topology of multiferroic vortices using in situ conductive atomic force microscopy, piezoresponse force microscopy, and kelvin-probe force microscopy at low temperatures. In addition to previously observed Schottky-like rectification at low bias [Phys. Rev. Lett., 104, 217601 (2010)], conductance spectra reveal that negatively charged tail-to-tail walls exhibit enhanced conduction at high forward bias, while positively charged head-to-head walls exhibit suppressed conduction at high reverse bias. Our results pave the way for understanding the semiconducting properties of the domains and domain walls in small-gap ferroelectrics.