npj: 综述—带电畴壁的物理及其应用

2018 年 12 月 25 日 知社学术圈

海归学者发起的公益学术平台

分享信息，整合资源

交流学术，偶尔风月

带电畴壁通常是两个畴之间的纳米级超薄界面；畴壁的两面由于自发极化存在法向分量的变化，畴壁常带有束缚电荷。与不同材料间的异质界面不同，带电畴壁（CDWs）可以在体材料中被反复创建、置换、擦除和重建。

来自捷克科学院物理研究所的Petr V. Yudin等，综述了近10年来带电畴壁背后的主要物理思想，概述了该领域最重要的理论和实验发现。人们为了CDWs的稳定性，通常需要用自由载流子对束缚电荷进行筛选，这可能导致沿畴壁传导方向产生巨大的二维电导率。通常名义上绝缘的铁电体中，畴壁上自由载流子的浓度可以接近金属值。因此，CDWs可以看作是嵌入绝缘材料体中的超薄可重构强导电层。这一特征对未来的纳米电子学非常有吸引力。过去十年，对CDWs的研究报道日益激增。在不同材料中可控、可重复制备CDWs、研究CDW特性和电荷补偿机制、发现光诱导效应和最终检测巨大的二维电导率等方面都取得了诸多突破。

该文近期发表于npj Computational Materials 4: 65 (2018)，英文标题与摘要如下，点击左下角“阅读原文”可以自由获取论文PDF。

Physics and applications of charged domain walls

Petr S. Bednyakov, Boris I. Sturman, Tomas Sluka, Alexander K. Tagantsev & Petr V. Yudin

The charged domain wall is an ultrathin (typically nanosized) interface between two domains; it carries bound charge owing to a change of normal component of spontaneous polarization on crossing the wall. In contrast to hetero-interfaces between different materials, charged domain walls (CDWs) can be created, displaced, erased, and recreated again in the bulk of a material. Screening of the bound charge with free carriers is often necessary for stability of CDWs, which can result in giant two-dimensional conductivity along the wall. Usually in nominally insulating ferroelectrics, the concentration of free carriers at the walls can approach metallic values. Thus, CDWs can be viewed as ultrathin reconfigurable strongly conductive sheets embedded into the bulk of an insulating material. This feature is highly attractive for future nanoelectronics. The last decade was marked by a surge of research interest in CDWs. It resulted in numerous breakthroughs in controllable and reproducible fabrication of CDWs in different materials, in investigation of CDW properties and charge compensation mechanisms, in discovery of light-induced effects, and, finally, in detection of giant two-dimensional conductivity. The present review is aiming at a concise presentation of the main physical ideas behind CDWs and a brief overview of the most important theoretical and experimental findings in the field.