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Li S, Wang F, Wang Y, Yang J, Wang X, Zhan X, He J, Wang Z. Van der Waals Ferroelectrics: Theories, Materials, and Device Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2301472. [PMID: 37363893 DOI: 10.1002/adma.202301472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 06/19/2023] [Indexed: 06/28/2023]
Abstract
In recent years, an increasing number of 2D van der Waals (vdW) materials are theory-predicted or laboratory-validated to possess in-plane (IP) and/or out-of-plane (OOP) spontaneous ferroelectric polarization. Due to their dangling-bond-free surfaces, interlayer charge coupling, robust polarization, tunable energy band structures, and compatibility with silicon-based technologies, vdW ferroelectric materials exhibit great promise in ferroelectric memories, neuromorphic computing, nanogenerators, photovoltaic devices, spintronic devices, and so on. Here, the very recent advances in the field of vdW ferroelectrics (FEs) are reviewed. First, theories of ferroelectricity are briefly discussed. Then, a comprehensive summary of the non-stacking vdW ferroelectric materials is provided based on their crystal structures and the emerging sliding ferroelectrics. In addition, their potential applications in various branches/frontier fields are enumerated, with a focus on artificial intelligence. Finally, the challenges and development prospects of vdW ferroelectrics are discussed.
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Affiliation(s)
- Shuhui Li
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Feng Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yanrong Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jia Yang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xinyuan Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xueying Zhan
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jun He
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Zhenxing Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
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2
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Wang J, Cheng F, Sun Y, Xu H, Cao L. Stacking engineering in layered homostructures: transitioning from 2D to 3D architectures. Phys Chem Chem Phys 2024; 26:7988-8012. [PMID: 38380525 DOI: 10.1039/d3cp04656g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Artificial materials, characterized by their distinctive properties and customized functionalities, occupy a central role in a wide range of applications including electronics, spintronics, optoelectronics, catalysis, and energy storage. The emergence of atomically thin two-dimensional (2D) materials has driven the creation of artificial heterostructures, harnessing the potential of combining various 2D building blocks with complementary properties through the art of stacking engineering. The promising outcomes achieved for heterostructures have spurred an inquisitive exploration of homostructures, where identical 2D layers are precisely stacked. This perspective primarily focuses on the field of stacking engineering within layered homostructures, where precise control over translational or rotational degrees of freedom between vertically stacked planes or layers is paramount. In particular, we provide an overview of recent advancements in the stacking engineering applied to 2D homostructures. Additionally, we will shed light on research endeavors venturing into three-dimensional (3D) structures, which allow us to proactively address the limitations associated with artificial 2D homostructures. We anticipate that the breakthroughs in stacking engineering in 3D materials will provide valuable insights into the mechanisms governing stacking effects. Such advancements have the potential to unlock the full capability of artificial layered homostructures, propelling the future development of materials, physics, and device applications.
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Affiliation(s)
- Jiamin Wang
- Changchun Institute of Optics, Fine Mechanics & Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, P. R. China.
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Fang Cheng
- State Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, Nanjing 210023, P. R. China
| | - Yan Sun
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China.
| | - Hai Xu
- Changchun Institute of Optics, Fine Mechanics & Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, P. R. China.
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Liang Cao
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China.
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Song G, Wu Y, Cao L, Li G, Zhang B, Liang F, Gao B. Non-volatile control of topological phase transition in an asymmetric ferroelectric In 2Te 2S monolayer. Phys Chem Chem Phys 2023; 25:24696-24704. [PMID: 37668094 DOI: 10.1039/d3cp02616g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
The coupling of topological electronic states and ferroelectricity is highly desired due to their abundant physical phenomenon and potential applications in multifunctional devices. However, it is difficult to achieve such a phenomenon in a single ferroelectric (FE) monolayer because the two polarized states are topologically equivalent. Here, we demonstrate that the symmetry of polarized states can be broken by constructing a Janus structure in a FE monolayer. We illustrate such a general idea by replacing a layer of Te atoms in the In2Te3 monolayer with S atoms. Using first-principles calculations, we show that the In2Te2S monolayer has two asymmetric polarized states, which are characterized by a metal and semiconductor, respectively. Importantly, as the spin-orbit coupling is included, a band gap (50.4 meV) is created in the metallic state, resulting in a non-trivial topological phase. Thus, it proves to be a feasible method to engineer non-volatile FE control of topological order in a single-phase system. We also demonstrate the underlying physical mechanism of topological phase transition, which is unveiled to be related to the weakened intrinsic electric field resulting from charge transfer. These interesting results provide a general way to design asymmetric FE materials and shed light on their potential application in non-volatile multifunctional devices.
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Affiliation(s)
- Guang Song
- Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China.
| | - Yangyang Wu
- Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China.
| | - Lei Cao
- Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China.
| | - Guannan Li
- Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China.
| | - Bingwen Zhang
- Fujian Key Laboratory of Functional Marine Sensing Materials, Minjiang University, Fuzhou 350108, China
| | - Feng Liang
- Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China.
| | - Benling Gao
- Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China.
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Xu X, Zhang T, Dai Y, Huang B, Ma Y. Nonvolatile electro-mechanical coupling in two-dimensional lattices. NANOSCALE HORIZONS 2023. [PMID: 37254561 DOI: 10.1039/d2nh00509c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Electro-mechanical coupling is of great interest for applications in sensors, actuators and energy harvesters. While the control of electrical charge by mechanical force has been studied extensively, reverse coupling is rarely explored, especially in two-dimensional (2D) lattices. Herein, we propose a novel mechanism for electro-mechanical coupling that realizes the electric field switching of the dimensions of a 2D lattice in a reversible and nonvolatile fashion, through the mediated strength of interlayer interactions in ferroelectric bilayer systems. Based on first-principles calculations, the validity of this mechanism is demonstrated in a series of real bilayer materials, i.e., MoS2/ReIrGe2S6, Sb/In2Se3 and bilayer In2Se3. The interface differences due to polarization play a crucial role in realizing such nonvolatile electro-mechanical coupling, and the underlying physical origin is discussed. These explored phenomena and insights offer a novel avenue for the highly desired nonvolatile electric field control of mechanical strain.
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Affiliation(s)
- Xilong Xu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Ting Zhang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Yandong Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
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Jin X, Zhang YY, Du S. Recent progress in the theoretical design of two-dimensional ferroelectric materials. FUNDAMENTAL RESEARCH 2023; 3:322-331. [PMID: 38933769 PMCID: PMC11197756 DOI: 10.1016/j.fmre.2023.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 01/11/2023] [Accepted: 02/02/2023] [Indexed: 03/06/2023] Open
Abstract
Two-dimensional (2D) ferroelectrics (FEs), which maintain stable electric polarization in ultrathin films, are a promising class of materials for the development of various miniature functional devices. In recent years, several 2D FEs with unique properties have been successfully fabricated through experiments. They have been found to exhibit some unique properties either by themselves or when they are coupled with other functional materials (e.g., ferromagnetic materials, materials with 5d electrons, etc.). As a result, several new types of 2D FE functional devices have been developed, exhibiting excellent performance. As a type of newly discovered 2D functional material, the number of 2D FEs and the exploration of their properties are still limited and this calls for further theoretical predictions. This review summarizes recent progress in the theoretical predictions of 2D FE materials and provides strategies for the rational design of 2D FE materials. The aim of this review is to provide guidelines for the design of 2D FE materials and related functional devices.
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Affiliation(s)
- Xin Jin
- University of the Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Yang Zhang
- University of the Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shixuan Du
- University of the Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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Bai Y, Mao N, Li R, Dai Y, Huang B, Niu C. Engineering Second-Order Corner States in 2D Multiferroics. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206574. [PMID: 36642812 DOI: 10.1002/smll.202206574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/18/2022] [Indexed: 06/17/2023]
Abstract
The understanding and manipulate of the second-order corner states are central to both fundamental physics and future topotronics applications. Despite the fact that numerous second-order topological insulators (SOTIs) are achieved, the efficient engineering in a given material remains elusive. Here, the emergence of 2D multiferroics SOTIs in SbAs and BP5 monolayers is theoretically demonstrated, and an efficient and straightforward way for engineering the nontrivial corner states by ferroelasticity and ferroelectricity is remarkably proposed. With ferroelectric polarization of SbAs and BP5 monolayers, the nontrivial corner states emerge in the mirror symmetric corners and are perpendicular to orientations of the in-plane spontaneous polarization. And remarkably the spatial distribution of the corner states can be effectively tuned by a ferroelastic switching. At the intermediate states of both ferroelectric and ferroelastic switchings, the corner states disappear. These finding not only combines exotic SOTIs with multiferroics but also pave the way for experimental discovery of 2D tunable SOTIs.
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Affiliation(s)
- Yingxi Bai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Ning Mao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Runhan Li
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Chengwang Niu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
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Zhang JJ, Altalhi T, Yakobson BI. Flexo-Ferroelectricity and a Work Cycle of a Two-Dimensional-Monolayer Actuator. ACS NANO 2023; 17:5121-5128. [PMID: 36853621 DOI: 10.1021/acsnano.3c00492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Well recognized mechanical flexibility of two-dimensional (2D) materials is shown to bring about unexpected behaviors to the recently discovered monolayer ferroelectrics, especially those displaying normal, off-plane polarization. A "ferro-flexo" coupling term is introduced into the energy expression, to account for the connection of ferroelectricity and bending (strain gradient) of the layer, to predict and quantify its spontaneous curvature and how it affects the phase transitions. With InP as a chemically specific representative example, the first-principles calculations indeed reveal strong coupling ∼P·ϰ between the ferroelectric polarization (P) and the curvature of the layer (ϰ ≡ 1/r), having profound consequences for both mechanics and ferroelectricity of the material. Due to flexural relaxation, the spontaneous polarization and the transition barrier rise significantly, leading to large changes in the Curie temperature, coercive field, and domain wall width and energy, based on Monte Carlo simulations. On the other hand, the polarization switching, characteristic to ferroelectrics, does induce an overall layer bending, enabling a conversion of electrical signal to movement as an actuator; its possible work-cycles and maximum work-efficiency are briefly discussed.
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Affiliation(s)
- Jun-Jie Zhang
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Tariq Altalhi
- Chemistry Department, Taif University, Taif 21974, Saudi Arabia
| | - Boris I Yakobson
- Chemistry Department, Taif University, Taif 21974, Saudi Arabia
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
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8
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Liang Y, Zheng F, Zhao P, Wang Q, Frauenheim T. Intrinsic Ferroelectric Quantum Spin Hall Insulator in Monolayer Na 3Bi with Surface Trimerization. J Phys Chem Lett 2022; 13:11059-11064. [PMID: 36416532 DOI: 10.1021/acs.jpclett.2c03270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Two-dimensional (2D) ferroelectric quantum spin Hall (FEQSH) insulator, which features coexisting ferroelectric and topologically insulating orders in two-dimension, is generally considered available only in engineered 2D systems. This is detrimental to the synthesis and application of next generation nonvolatile functional candidates. Therefore, exploring the intrinsic 2D FEQSH insulator is crucial. Here, by means of first-principles, we report a long-thought intrinsic 2D FEQSH insulator in monolayer Na3Bi with surface trimerization. The material harbors merits including large ferroelectric polarization, sizable nontrivial band gap, and low switching barrier, which are particularly beneficial for the detection and observation of ferroelectric topologically insulating states. Also, it is capable of nonvolatile switching of nontrivial spin textures via inherent ferroelectricity. The fantastic combination of excellent ferroelectric and topological phases in intrinsic the Na3Bi monolayer serves as an alluring platform for accelerating both scientific discoveries and innovative applications.
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Affiliation(s)
- Yan Liang
- College of Physics and Optoelectronic Engineering, Faculty of Information Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100, People's Republic of China
| | - Fulu Zheng
- Bremen Center for Computational Materials Science, University of Bremen, Bremen, 28359, Germany
| | - Pei Zhao
- College of Physics and Optoelectronic Engineering, Faculty of Information Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100, People's Republic of China
| | - Qiang Wang
- Key laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066104, People's Republic of China
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen, Bremen, 28359, Germany
- Beijing Computational Science Research Center, Beijing, 100193, People's Republic of China
- Shenzhen JL Computational Science and Applied Research Institute, Shenzhen, 518109, People's Republic of China
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9
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Singh B, Lin H, Bansil A. Topology and Symmetry in Quantum Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2201058. [PMID: 36414399 DOI: 10.1002/adma.202201058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/13/2022] [Indexed: 06/16/2023]
Abstract
Interest in topological materials continues to grow unabated in view of their conceptual novelties as well as their potential as platforms for transformational new technologies. Electronic states in a topological material are robust against perturbations and support unconventional electromagnetic responses. The first-principles band-theory paradigm has been a key player in the field by providing successful prediction of many new classes of topological materials. This perspective presents a cross section through the recent work on understanding the role of geometry and topology in generating topological states and their responses to external stimuli, and as a basis for connecting theory and experiment within the band theory framework. In this work, effective strategies for topological materials discovery and impactful directions for future topological materials research are also commented.
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Affiliation(s)
- Bahadur Singh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Hsin Lin
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, Massachusetts, 02115, USA
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10
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Xuan X, Zhang Z, Chen C, Guo W. Robust Quantum Anomalous Hall States in Monolayer and Few-Layer TiTe. NANO LETTERS 2022; 22:5379-5384. [PMID: 35776156 DOI: 10.1021/acs.nanolett.2c01421] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Quantum anomalous Hall (QAH) insulators possess exotic properties driven by novel topological physics, but related studies and potential applications have been hindered by the ultralow temperatures required to sustain the operating mechanisms dictated by key material parameters. Here, using first-principles calculations, we predict a robust QAH state in monolayer TiTe that exhibits a high ferromagnetic Curie temperature of 650 K and a sizable band gap of 261 meV. These outstanding benchmark properties stem from the Te atom's large size that favors ferromagnetic kinetic exchange with the neighboring Ti atoms and strong spin-orbit coupling that creates a QAH state by adding a mass term to the Dirac half-semimetal state. Remarkably, the ferromagnetic order remains robust against interlayer stacking via the d-pz/py-pz-d super-super exchange, generating unprecedented QAH states in few-layer configurations with enhanced Curie temperatures and higher Chern numbers. These results signify layered TiTe to be a prime template for exploring novel QAH physics at ambient and higher temperatures.
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Affiliation(s)
- Xiaoyu Xuan
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Zhuhua Zhang
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Changfeng Chen
- Department of Physics and Astronomy, University of Nevada, Las Vegas, Nevada 89154, United States
| | - Wanlin Guo
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
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Huang J, Duan X, Jeon S, Kim Y, Zhou J, Li J, Liu S. On-demand quantum spin Hall insulators controlled by two-dimensional ferroelectricity. MATERIALS HORIZONS 2022; 9:1440-1447. [PMID: 35438108 DOI: 10.1039/d2mh00334a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We propose a new class of quantum materials, type-II two-dimensional ferroelectric topological insulators (2DFETIs), which allow non-volatility and an on-off switch of quantum spin Hall states. A general strategy is developed to realize type-II 2DFETIs using only topologically trivial 2D ferroelectrics. The built-in electric field arising from the out-of-plane polarization across the bilayer heterostrucuture of 2D ferroelectrics enables robust control of the band gap size and band inversion strength, which can be utilized to manipulate the topological phase transitions on-demand. Using first-principles calculations with hybrid density functionals, we demonstrate that a series of bilayer heterostructures are type-II 2DFETIs characterized with a direct coupling between the band topology and polarization state. We propose a few 2DFETI-based quantum electronics, including domain-wall quantum circuits and topological memristors.
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Affiliation(s)
- Jiawei Huang
- Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
- Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang 310024, China.
| | - Xu Duan
- Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang 310024, China.
- Fudan University, Shanghai 200433, China
| | - Sunam Jeon
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Korea
| | - Youngkuk Kim
- Department of Physics, Sungkyunkwan University, Suwon 16419, Korea
| | - Jian Zhou
- Center for Alloy Innovation and Design, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jian Li
- Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang 310024, China.
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Shi Liu
- Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang 310024, China.
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
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12
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Wu M, Li J. Sliding ferroelectricity in 2D van der Waals materials: Related physics and future opportunities. Proc Natl Acad Sci U S A 2021; 118:e2115703118. [PMID: 34862304 PMCID: PMC8685923 DOI: 10.1073/pnas.2115703118] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Indexed: 11/18/2022] Open
Abstract
Near the 100th anniversary of the discovery of ferroelectricity, so-called sliding ferroelectricity has been proposed and confirmed recently in a series of experiments that have stimulated remarkable interest. Such ferroelectricity exists widely and exists only in two-dimensional (2D) van der Waals stacked layers, where the vertical electric polarization is switched by in-plane interlayer sliding. Reciprocally, interlayer sliding and the "ripplocation" domain wall can be driven by an external vertical electric field. The unique combination of intralayer stiffness and interlayer slipperiness of 2D van der Waals layers greatly facilitates such switching while still maintaining environmental and mechanical robustness at ambient conditions. In this perspective, we discuss the progress and future opportunities in this behavior. The origin of such ferroelectricity as well as a general rule for judging its existence are summarized, where the vertical stacking sequence is crucial for its formation. This discovery broadens 2D ferroelectrics from very few material candidates to most of the known 2D materials. Their low switching barriers enable high-speed data writing with low energy cost. Related physics like Moiré ferroelectricity, the ferroelectric nonlinear anomalous Hall effect, and multiferroic coupling are discussed. For 2D valleytronics, nontrivial band topology and superconductivity, their possible couplings with sliding ferroelectricity via certain stacking or Moiré ferroelectricity also deserve interest. We provide critical reviews on the current challenges in this emerging area.
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Affiliation(s)
- Menghao Wu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China;
| | - Ju Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
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