帶電疇壁通常是兩個疇之間的納米級超薄界面；疇壁的兩面由於自發極化存在法向分量的變化，疇壁常帶有束縛電荷。與不同材料間的異質界面不同，帶電疇壁（CDWs）可以在體材料中被反覆創建、置換、擦除和重建。
來自捷克科學院物理研究所的Petr V. Yudin等，綜述了近10年來帶電疇壁背後的主要物理思想，概述了該領域最重要的理論和實驗發現。人們為了CDWs的穩定性，通常需要用自由載流子對束縛電荷進行篩選，這可能導致沿疇壁傳導方向產生巨大的二維電導率。通常名義上絕緣的鐵電體中，疇壁上自由載流子的濃度可以接近金屬值。因此，CDWs可以看作是嵌入絕緣材料體中的超薄可重構強導電層。這一特徵對未來的納米電子學非常有吸引力。過去十年，對CDWs的研究報道日益激增。在不同材料中可控、可重複製備CDWs、研究CDW特性和電荷補償機制、發現光誘導效應和最終檢測巨大的二維電導率等方面都取得了諸多突破。
該文近期發表於npj Computational Materials 4: 65 (2018)，英文標題與摘要如下，點擊https://www.nature.com/articles/s41524-018-0121-8可以自由獲取論文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.
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