Nonvolatile Electric-Field Control of Inversion Symmetry
Lucas Caretta, Yu-Tsun Shao, Jia Yu, Antonio B. Mei, Bastien F. Grosso, Cheng Dai, Piush Behera, Daehun Lee, Margaret McCarter, Eric Parsonnet, Harikrishnan K. … 展开作者
Lucas Caretta, Yu-Tsun Shao, Jia Yu, Antonio B. Mei, Bastien F. Grosso, Cheng Dai, Piush Behera, Daehun Lee, Margaret McCarter, Eric Parsonnet, Harikrishnan K. P., Fei Xue, Ed Barnard, Steffen Ganschow, Archana Raja, Lane W. Martin, Long-Qing Chen, Manfred Fiebig, Keji Lai, Nicola A. Spaldin, David A. Muller, Darrell G. Schlom, Ramamoorthy Ramesh
备注：
L Caretta and Y-T Shao contributed equally. 64 pages, 4 figures, 25 supplemental figures, 1 supplemental table
In condensed-matter systems, competition between ground states at phase boundaries can lead to significant changes in material properties under external stimuli, particularly when these ground states have different crystal symmetries. A key scientific and technological challenge is to stabilize and control coexistence of symmetry-distinct phases with external stimuli. Using BiFeO3 (BFO) layers confined between layers of the dielectric TbScO3 as a model system, we stabilize the mixed-phase coexistence of centrosymmetric and non-centrosymmetric BFO phases with antipolar, insulating and polar, semiconducting behavior, respectively at room temperature. Application of in-plane electric (polar) fields can both remove and introduce centrosymmetry from the system resulting in reversible, nonvolatile interconversion between the two phases. This interconversion between the centrosymmetric insulating and non-centrosymmetric semiconducting phases coincides with simultaneous changes in the non-linear optical response of over three orders of magnitude, a change in resistivity of over five orders of magnitude, and a change in the polar order. Our work establishes a materials platform allowing for novel cross-functional devices which take advantage of changes in optical, electrical, and ferroic responses.
Electric field control of nonvolatile four-state magnetization at room temperature
我们发现在多铁性六角铁氧体Ba $_{0.52}$ Sr $_{2.48}$ Co $_{2}$ Fe $_{24}$ O $_{41}$单晶中在室温下实现了大的逆磁电效应，其中电极化的强度在低磁场（约5 mT）下的快速变化被认为是大的逆磁电（ME）磁化率（3200 ps/m）的原因.磁化强度的调制达到0.62 $μ$ $_{B}$ /f. u。在1.14 MV/m的电场中。我们进一步发现，由不同的ME极化诱导的四个ME状态表现出独特的，非易失性的磁化强度与电场曲线，这可以近似地描述了一个有效的自由能与一组不同的ME系数。
Spin transport through magnetic insulators has been demonstrated in a variety of materials and is an emerging pathway for next-generation spin-based computing. To modulate spin transport in these systems, one typically applies a sufficiently strong magnetic field to allow for deterministic control of magnetic order. Here, we make use of the well-known multiferroic magnetoelectric, BiFeO3, to demonstrate non-volatile, hysteretic, electric-field control of thermally excited magnon current in the absence of an applied magnetic field. These findings are an important step toward magnon-based device…
Quantum spin Hall (QSH) insulator materials feature topologically protected edge states that can drastically reduce dissipation and are useful for the next-generation electronics. However, the nonvolatile control of topological edge state is still a challenge. In this paper, based on first-principles calculations, the switchable topological states are found in the van der Waals (vdW) heterostructures consisting of two dimensional (2D) Bi(111) bilayer (BL) and α-In2Se3 by reversing the electric polarization of the ferroelectric α-In2Se3. The topological switching results from the different char…
Reversible and nonvolatile manipulation of the spin-orbit interaction in ferroelectric field-effect transistors based on a two-dimensional bismuth oxychalcogenide
Energy-efficient programmable photonic integrated circuits (PICs) are the cornerstone of on-chip classical and quantum optical technologies. Optical phase shifters constitute the fundamental building blocks which enable these programmable PICs. Thus far, carrier modulation and thermo-optical effect are the chosen phenomena for ultrafast and low-loss phase shifters, respectively; however, the state and information they carry are lost once the power is turned off-they are volatile. The volatility not only compromises energy efficiency due to their demand for constant power supply, but also precl…
Electric-Switchable Chiral Magnons in PT-Symmetric Antiferromagnets
Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Advanced Functional Materials and Mesoscopic Physics, School of Physics, Xi’an Jiaotong University（西安交通大学物理学院）；Division of Physics and Applied Physics, School of Physics and Mathematical Sciences, Nanyang Technological University（南洋理工大学物理与数学科学学院）；Department of Physics, University of Science and Technology of China（中国科学技术大学物理系）；Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University（华南师范大学物理学院）
Ferroelectric Band Twinning from Pair-State Symmetry
Singapore University of Technology and Design（新加坡科技设计大学）；University of Wollongong（伍伦贡大学）；Tiangong University（天津工业大学）；Xiangtan University（湘潭大学）；Beijing Institute of Technology（北京理工大学）
In systems with time-reversal symmetry, the orbital magnetization is zero in equilibrium. Recently, it has been proposed that the orbital magnetization can be induced by an electric current in a helical crystal structure in the same manner as that in a classical solenoid. In this paper, we extend this theory and study the current-induced orbital magnetization in a broader class of systems without inversion symmetry. First, we consider polar metals which have no inversion symmetry. We find that the current-induced orbital magnetization appears in a direction perpendicular to the electric curren…
Axion field induced topological magneto-electric response has attracted lots of attentions since it was first proposed by Qi et al. in 2008. Here we find a new type of anti-commutative magneto-electric response β^ξ(ω), which can induce a dynamical magneto-electric current driven by a time-varying magnetic field. Unlike the Chern-Simons Axion term, this magneto-electric response term is gauge-independent and non-quantized, and manifests in the systems breaking the symmetries of the time-reversal, inversion and mirror. In particular, we propose the antiferromagnetic material Mn_{2}Bi_{2}Te_{5} a…
Crafting the strain state in epitaxial thin films: A case study of CoFe2O4 films on Pb(Mg,Nb)O3-PbTiO3
无论是从基础科学的角度还是从应用的角度，都已经广泛地研究了电和磁性质的应变依赖性。通过场致极化旋转（PRO）和极化重取向（PRE）在压电单晶中的机电耦合可以在薄膜/衬底外延异质结构中提供有效应变。然而，PRO和PRE的特定途径是一个复杂的热力学过程，取决于化学组成、温度、电场和机械负荷。本文系统地研究了不同初始相和取向结构的Pb（Mg，Nb）O_3-PbTiO_3单晶的场致相变随温度的变化。不同类型的应变，挥发性/非挥发性和双轴/单轴，已被测量的宏观和原位X射线衍射技术。此外，通过磁各向异性测量研究了外延Mn掺杂CoFe 2 O 4薄膜的应变状态，其中巨磁电耦合已被证明。
Ferrimagnets, which contain the advantages of both ferromagnets (detectable moments) and antiferromagnets (ultrafast spin dynamics), have recently attracted great attention. Here we report the optimization of epitaxial growth of a tetragonal perpendicularly magnetized ferrimagnet Mn2Ga on MgO. Electrical transport, magnetic properties and the anomalous Hall effect (AHE) were systematically studied. Furthermore, we successfully integrated high-quality epitaxial ferrimagnetic Mn2Ga thin films onto ferroelectric PMN-PT single crystals with a MgO buffer layer. It was found that the AHE of such a f…
Magnetic Compton scattering is an established tool for probing magnetism in ferromagnetic or ferrimagnetic materials with a net spin polarization. Here we show that, counterintuitively, {\it non-magnetic} systems can also have a non-zero magnetic Compton profile, provided that space-inversion symmetry is broken. The magnetic Compton profile is antisymmetric in momentum and, if the inversion symmetry is broken by an electric-field switchable ferroelectric distortion, can be reversed using an electric field. We show that the underlying physics of the magnetic Compton profile and its electrical c…
