Two-dimensional(2D)ferroelectric(FE)systems are promising candidates for non-volatile nanodevices.Previous studies mainly focused on 2D compounds.Though counter-intuitive,here we propose several new phases of telluriu...Two-dimensional(2D)ferroelectric(FE)systems are promising candidates for non-volatile nanodevices.Previous studies mainly focused on 2D compounds.Though counter-intuitive,here we propose several new phases of tellurium with(anti)ferroelectricity.Two-dimensional films can be viewed as a collection of one-dimensional chains,and lone-pair instability is responsible for the(anti)ferroelectricity.The total polarization is determined to be 0.34×10^(-10)C/m for the FE ground state.Due to the local polarization field in the FE film,we show a large Rashba splitting(α_(R)~2 eV·?)with nonzero spin Hall conductivity for experimental detection.Furthermore,a dipole-like distribution of Berry curvature is verified,which may facilitate a nonlinear Hall effect.Because Rashba-splitting/Berry-curvature distributions are fully coupled with a polarization field,they can be reversed through FE phase transition.Our results not only broaden the elemental FE materials,but also shed light on their intriguing transport phenomena.展开更多
The group-V monolayers(MLs)have been studied intensively after the experimental fabrication of two-dimensional(2D)graphene and black phosphorus.The observation of novel quantum phenomena,such as quantum spin Hall effe...The group-V monolayers(MLs)have been studied intensively after the experimental fabrication of two-dimensional(2D)graphene and black phosphorus.The observation of novel quantum phenomena,such as quantum spin Hall effect and ferroelectricity in group-V elemental layers,has attracted tremendous attention because of the novel physics and promising applications for nanoelectronics in the 2D limit.In this review,we comprehensively review recent research progress in engineering of topology and ferroelectricity,and several effective methods to control the quantum phase transition are discussed.We then introduce the coupling between topological orders and ferroelectric orders.The research directions and outlooks are discussed at the end of the perspective.It is expected that the comprehensive overview of topology and ferroelectricity in 2D group-V materials can provide guidelines for researchers in the area and inspire further explorations of interplay between multiple quantum phenomena in low-dimensional systems.展开更多
The coupling between electric ordering and magnetic ordering in two-dimensional(2D)materials is important for both fundamental research of 2D multiferroics and future development of magnetism-based information storage...The coupling between electric ordering and magnetic ordering in two-dimensional(2D)materials is important for both fundamental research of 2D multiferroics and future development of magnetism-based information storage and operation.Here,we introduce a scheme for realizing a magnetic phase transition through the transition of electric ordering.We take CuMoP_(2)S_(6) monolayer as an example,which is a member of the large 2D transition-metal chalcogen-phosphates family.Based on first-principles calculations,we find that it is a multiferroic with unprecedented characters,namely,it exhibits two different phases:an antiferroelectric-antiferromagnetic phase and a ferroelectric-ferromagnetic phase,in which the electric and magnetic orderings are strongly coupled.Importantly,the electric polarization is out-of-plane,so the magnetism can be readily switched by using the gate electric field.Our finding reveals a series of 2D multiferroics with special magnetoelectric coupling,which hold great promise for experimental realization and practical applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11904317 and 12204029)the Funding of Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(Grant No.2020R01002)the Natural Science Foundation of Zhejiang Province(Grant Nos.LY23E020010 and LQ23A040013)。
文摘Two-dimensional(2D)ferroelectric(FE)systems are promising candidates for non-volatile nanodevices.Previous studies mainly focused on 2D compounds.Though counter-intuitive,here we propose several new phases of tellurium with(anti)ferroelectricity.Two-dimensional films can be viewed as a collection of one-dimensional chains,and lone-pair instability is responsible for the(anti)ferroelectricity.The total polarization is determined to be 0.34×10^(-10)C/m for the FE ground state.Due to the local polarization field in the FE film,we show a large Rashba splitting(α_(R)~2 eV·?)with nonzero spin Hall conductivity for experimental detection.Furthermore,a dipole-like distribution of Berry curvature is verified,which may facilitate a nonlinear Hall effect.Because Rashba-splitting/Berry-curvature distributions are fully coupled with a polarization field,they can be reversed through FE phase transition.Our results not only broaden the elemental FE materials,but also shed light on their intriguing transport phenomena.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974307 and 61574123)Zhejiang Provincial Natural Science Foundation,China(Grant No.D19A040001)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe 2DMOST,Shenzhen University(Grant No.2018028).
文摘The group-V monolayers(MLs)have been studied intensively after the experimental fabrication of two-dimensional(2D)graphene and black phosphorus.The observation of novel quantum phenomena,such as quantum spin Hall effect and ferroelectricity in group-V elemental layers,has attracted tremendous attention because of the novel physics and promising applications for nanoelectronics in the 2D limit.In this review,we comprehensively review recent research progress in engineering of topology and ferroelectricity,and several effective methods to control the quantum phase transition are discussed.We then introduce the coupling between topological orders and ferroelectric orders.The research directions and outlooks are discussed at the end of the perspective.It is expected that the comprehensive overview of topology and ferroelectricity in 2D group-V materials can provide guidelines for researchers in the area and inspire further explorations of interplay between multiple quantum phenomena in low-dimensional systems.
基金Supported by the National Key R&D Program of China(Grant No.2019YFE0112000)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LR21A040001)the National Natural Science Foundation of China(Grant No.11974307,12088101,11991060,and U1930402).
文摘The coupling between electric ordering and magnetic ordering in two-dimensional(2D)materials is important for both fundamental research of 2D multiferroics and future development of magnetism-based information storage and operation.Here,we introduce a scheme for realizing a magnetic phase transition through the transition of electric ordering.We take CuMoP_(2)S_(6) monolayer as an example,which is a member of the large 2D transition-metal chalcogen-phosphates family.Based on first-principles calculations,we find that it is a multiferroic with unprecedented characters,namely,it exhibits two different phases:an antiferroelectric-antiferromagnetic phase and a ferroelectric-ferromagnetic phase,in which the electric and magnetic orderings are strongly coupled.Importantly,the electric polarization is out-of-plane,so the magnetism can be readily switched by using the gate electric field.Our finding reveals a series of 2D multiferroics with special magnetoelectric coupling,which hold great promise for experimental realization and practical applications.
