Large family of two-dimensional ferroelectric metals discovered via machine learning

作     者：Xing-Yu Ma Hou-Yi Lyu Kuan-Rong Hao Yi-Ming Zhao Xiaofeng Qian Qing-Bo Yan Gang Su 马星宇;吕厚毅;郝宽荣;Yi-Ming Zhao;钱晓峰;闫清波;苏刚

作者机构：School of Physical SciencesUniversity of Chinese Academy of SciencesBeijing 100049China Center of Materials Science and Optoelectronics EngineeringCollege of Materials Science and Optoelectronic TechnologyUniversity of Chinese Academy of SciencesBeijing 100049China Department of Materials Science and EngineeringCollege of Engineering and College of ScienceTexas A&M UniversityCollege StationTX 77843USA Kavli Institute for Theoretical Sciencesand CAS Center for Excellence in Topological Quantum ComputationUniversity of Chinese Academy of SciencesBeijing 100190China 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2021年第66卷第3期

页      面：233-242,M0003页

核心收录：

学科分类：12[管理学] 1201[管理学-管理科学与工程(可授管理学、工学学位)] 07[理学] 070205[理学-凝聚态物理] 081104[工学-模式识别与智能系统] 08[工学] 0835[工学-软件工程] 0811[工学-控制科学与工程] 0812[工学-计算机科学与技术（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：the National Key R&D Program of China(2018YFA0305800) the Strategic Priority Research Program of Chinese Academy of Sciences(XDB28000000) the National Natural Science Foundation of China(11834014) Beijing Municipal Science and Technology Commission(Z191100007219013) University of Chinese Academy of Sciences 

主　　题：Ferroelectric metal 2D ferroelectricity Multiferroics Ab initio calculations Machine learning 

摘      要：Ferroelectricity and metallicity are usually believed not to coexist because conducting electrons would screen out static internal electric *** 1965,Anderson and Blount proposed the concept offerroelectric metal,however,it is only until recently that very rare ferroelectric metals were ***,by combining high-throughput ab initio calculations and data-driven machine learning method with new electronic orbital based descriptors,we systematically investigated a large family(2964)of two-dimensional(2D)bimetal phosphates,and discovered 60 stable ferroelectrics with out-of-plane polarization,including 16 ferroelectric metals and 44 ferroelectric semiconductors that contain seven *** ferroelectricity origins from spontaneous symmetry breaking induced by the opposite displacements of bimetal atoms,and the full-d-orbital coinage metal elements cause larger displacements and polarization than other *** 2D ferroelectric metals,the odd electrons per unit cell without spin polarization may lead to a half-filled energy band around Fermi level and is responsible for the *** is revealed that the conducting electrons mainly move on a single-side surface of the 2D layer,while both the ionic and electric contributions to polarization come from the other side and are vertical to the above layer,thereby causing the coexistence of metallicity and *** der Waals heterostructures based on ferroelectric metals may enable the change of Schottky barrier height or the Schottky-Ohmic contact type and induce a dramatic change of their vertical transport *** work greatly expands the family of 2D ferroelectric metals and will spur further exploration of 2D ferroelectric metals.