Mundy J A, Schaab J, Kumagai Y, Cano A, Stengel M, Krug I P, Gottlob D M, Dog Anay H, Holtz M E, Held R, Yan Z, Bourret E, Schneider C M, Schlom D G, Muller D A, Ramesh R, Spaldin N A, Meier D
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
Department of Materials, ETH Zurich, 8093 Zürich, Switzerland.
Nat Mater. 2017 Jun;16(6):622-627. doi: 10.1038/nmat4878. Epub 2017 Mar 20.
Ferroelectric domain walls hold great promise as functional two-dimensional materials because of their unusual electronic properties. Particularly intriguing are the so-called charged walls where a polarity mismatch causes local, diverging electrostatic potentials requiring charge compensation and hence a change in the electronic structure. These walls can exhibit significantly enhanced conductivity and serve as a circuit path. The development of all-domain-wall devices, however, also requires walls with controllable output to emulate electronic nano-components such as diodes and transistors. Here we demonstrate electric-field control of the electronic transport at ferroelectric domain walls. We reversibly switch from resistive to conductive behaviour at charged walls in semiconducting ErMnO. We relate the transition to the formation-and eventual activation-of an inversion layer that acts as the channel for the charge transport. The findings provide new insight into the domain-wall physics in ferroelectrics and foreshadow the possibility to design elementary digital devices for all-domain-wall circuitry.
铁电畴壁因其独特的电子特性，作为功能性二维材料具有巨大的潜力。特别引人关注的是所谓的带电畴壁，其中极性失配会导致局部发散的静电势，这需要电荷补偿，从而改变电子结构。这些畴壁可以表现出显著增强的导电性，并作为电路路径。然而，全畴壁器件的发展还需要具有可控输出的畴壁，以模拟二极管和晶体管等电子纳米元件。在这里，我们展示了铁电畴壁处电子输运的电场控制。我们在半导体ErMnO₃的带电畴壁处可逆地从电阻行为切换到导电行为。我们将这种转变与作为电荷传输通道的反型层的形成及最终激活联系起来。这些发现为铁电体中的畴壁物理提供了新的见解，并预示了为全畴壁电路设计基本数字器件的可能性。
