Vortex Domain Walls in Ferroelectrics.

Hong, Zijian; Das, Sujit; Nelson, Christopher; Yadav, Ajay; Wu, Yongjun; Junquera, Javier; Chen, Long-Qing; Martin, Lane W et al. · Nano Lett · 2021

basic_science · Level V

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Abstract

Controlling the domain formation in ferroelectric materials at the nanoscale is a fertile ground to explore emergent phenomena and their technological prospects. For example, charged ferroelectric domain walls in BiFeO<sub>3</sub> and ErMnO<sub>3</sub> exhibit significantly enhanced conductivity which could serve as the foundation for next-generation circuits (Estévez and Laurson, <i>Phys. Rev. B</i> <b>2015</b>, <i>91</i>, 054407). Here, we describe a concept in which polar vortices perform the same role as a ferroelectric domain wall in classical domain structures with the key difference being that the polar vortices can accommodate charged (<i>i.e</i>., head-to-head and tail-to-tail) domains, for example, in ferroelectric PbTiO<sub>3</sub>/dielectric SrTiO<sub>3</sub> superlattices. Such a vortex domain wall structure can be manipulated in a reversible fashion under an external applied field.