DOCSLIB.ORG

Large Linear Magnetoelectric Effect and Field-Induced Ferromagnetism

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Large Linear Magnetoelectric Effect and Field-Induced Ferromagnetism Shen et al. NPG Asia Materials (2019) 11:50 https://doi.org/10.1038/s41427-019-0151-9 NPG Asia Materials ARTICLE Open Access Large linear magnetoelectric effect and field-induced ferromagnetism and ferroelectricity in DyCrO4 Xudong Shen1,2, Long Zhou1,2, Yisheng Chai1,3,YanWu4, Zhehong Liu1,2,YunyuYin1,2,HuiboCao4, Clarina Dela Cruz4, Young Sun 1,2, Changqing Jin1,2,AngelMuñoz5,JoséAntonio Alonso 6 and Youwen Long1,2,7 Abstract All the magnetoelectric properties of scheelite-type DyCrO4 are characterized by temperature- and field- dependent magnetization, specific heat, permittivity, electric polarization, and neutron diffraction measurements. Upon application of a magnetic field within ±3 T, the nonpolar collinear antiferromagnetic structure leads to a large linear magnetoelectric effect with a considerable coupling coefficient. An applied electric field can induce the converse linear magnetoelectric effect, realizing magnetic field control of ferroelectricity and electric field control of magnetism. Furthermore, a higher magnetic field (>3 T) can cause a metamagnetic transition from the initially collinear antiferromagnetic structure to a canted structure, generating a large ferromagnetic magnetization −1 up to 7.0 μB f.u. Moreover, the new spin structure can break the space inversion symmetry, yielding ferroelectric polarization, which leads to coupling of ferromagnetism and ferroelectricity with a large ferromagnetic component. 1234567890():,; 1234567890():,; 1234567890():,; 1234567890():,; Introduction maximum α obtained for a nonpolar antiferromagnetic − The linear magnetoelectric (ME) effect and multi- (AFM) structure is <40 ps m 1 usually6. It is important to ferroicity enable control of polarization P (magnetization obtain a larger and constant ME effect in wider tem- M) by a magnetic (electric) field, which is beneficial for perature and/or magnetic field regions for potential applications in spintronic devices, nonvolatile memories, applications. – high-sensitivity magnetic field sensors, etc1 5. In the linear In the 1990s, the term “multiferroics” was proposed to ME effect, the induced electric polarization or magneti- describe materials that simultaneously exhibit more than zation is proportional to the applied magnetic field H or one ferroic order, such as ferromagnetism, ferroelectricity, 10 electric field E, which can be expressed as P = αH or μ0M and ferroelasticity, in a single phase . Among the dif- 6,7 = αE , where α denotes the linear ME coefficient and μ0 ferent multiferroics, the spin-ordering-induced ferro- denotes the magnetic permeability of a vacuum. Since the electrics (i.e., ME multiferroics) attracted significant 11–15 first observation of the linear ME effect in Cr2O3 in the attention owing to the strong ME coupling . Based on 1960s8,9, the search for single-phase ME materials with the magnetic space group, collinear ferromagnetic (FM) larger α values has attracted much attention. The spin alignment cannot break the spatial inversion sym- metry. Therefore, electric polarization in single-phase ME multiferroics is often induced by some peculiar AFM or Correspondence: Youwen Long ([email protected]) canted AFM spin structures instead of collinear ferro- 1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, magnetism16. Consequently, the magnetic moment is too – Chinese Academy of Sciences, Beijing 100190, China small to be effectively controlled17 19. It is very challen- 2School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China ging to obtain a material with strongly coupled Full list of author information is available at the end of the article. © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a linktotheCreativeCommons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Shen et al. NPG Asia Materials (2019) 11:50 Page 2 of 8 FM–ferroelectric properties and a considerable magnetic system (Quantum Design, MPMS-3). Both zero field- moment. cooling (FC) and FC modes were employed for χ mea- 5+ DyCrO4 has a rare Cr valence state. Under ambient surements at 0.01 T. The field-dependent M measure- conditions, it crystallizes into a zircon-type crystal struc- ments were performed at different temperatures. The 20,21 ture with the space group of I41/amd . An FM phase specific heat (Cp) and electrical properties were measured transition with a large magnetocaloric effect occurs at using a physical property measurement system (Quantum 22–24 approximately 23 K . Moreover, the zircon-type Design, PPMS-9T). The Cp data were acquired during structure is sensitive to external pressure. A pressure- cooling in the range of 50–2 K with different magnetic induced irreversible structural phase transition toward a fields. For the measurements of the relative dielectric scheelite-type new phase with I41/a symmetry has already constant εr, dielectric loss tanδ, and pyroelectric current been reported25. In contrast to the FM zircon phase, the density (J), the specimens were fabricated as thin plates – scheelite phase exhibits a long-range AFM transition26 28. with a typical surface area of 1–2mm2 and a thickness of In this study, scheelite-type DyCrO4 was prepared in a 0.2 mm. Silver electrodes were coated onto the two sur- polycrystalline form by a high-pressure and moderate- faces of the plate for electrical measurements. Different temperature treatment method (see “Materials and frequencies of 1 kHz, 10 kHz, 0.1 MHz, and 1 MHz were methods” below). Based on the powder X-ray diffraction applied for the dielectric constant and dielectric loss (XRD) and neutron diffraction results, there is no dis- measurements at selected magnetic fields in the range of cernable impurity phase, such as the residual FM zircon 0–9 T with intervals of 1 T using an Agilent E4980A phase, or decomposed DyCrO3 perovskite phase (see Precision LCR Meter while sweeping the temperature − Supplementary Figs. S1 and S2 for details). This com- from 2 to 50 K with a heating rate of 2 K min 1. The pound has a nonpolar collinear AFM ground state with pyroelectric current was measured by a Keithley 6517B zero magnetic field. Within μ0H ≈ ±3 T, a large and almost precise electrometer while sweeping the temperature − constant linear ME effect is observed, enabling H control from 2 to 50 K at a rate of 2 K min 1. Before this mea- of P and E control of M. Under higher magnetic fields, a surement, the sample was poled from 50 to 2 K with a −1 metamagnetic transition occurs and is accompanied by a poling electric field of Epol = ±1.08 MV m . Once the large FM magnetization. Furthermore, the new spin temperature was decreased to 2 K, Epol was switched off structure can break the spatial inversion symmetry and and J was measured as described above. The magnetic- thereby generate ferroelectric polarization. The presented field-dependent current was measured while sweeping the −1 DyCrO4 paves the way for novel investigations on magnetic field at a rate of 0.01 T s . In these measure- simultaneous direct and converse linear ME effects and ments, the PPMS was used to provide low-temperature FM–ferroelectrics with large magnetic moments. and magnetic field environments. The electric polariza- tion (P) was obtained by integrating J as a function of Materials and methods time. In addition, we measured the electric-field-induced Sample synthesis and XRD magnetization using MPMS-3 with different electric fields To fabricate the scheelite-type DyCrO4 sample, the produced by the Keithley 6517B electrometer. Before the zircon-type sample was prepared at ambient pressure as a measurement, the sample was cooled from 50 to 10 K at a 26 −1 −1 precursor, as reported in a previous study . The prepared rate of 2 K min at Epol = 0.5 MV m and μ0H = 4T. zircon-type DyCrO4 powders were pressed into a golden Once the temperature was decreased to 10 K, both Epol cylinder with a diameter of 4.0 mm and height of 3.0 mm. and H were switched off, and then M was measured The cylinder was treated at 6–8 GPa and 700–750 K for during heating from 10 to 26.5 K at fixed temperatures 10–30 min on a cubic-anvil-type high-pressure apparatus and selected electric fields. using pyrophyllite as a pressure transmission medium. When the heating power was turned off, the pressure was Neutron diffraction measurements slowly released. The crystal quality and structure were The neutron powder diffraction (NPD) measurements analyzed by powder XRD using a Huber diffractometer were carried out using the constant-wavelength high- with Cu Kα1 radiation at 40 kV and 30 mA. The XRD data resolution neutron powder diffractometer HB2A at Oak were acquired at room temperature in the 2θ range of Ridge National Laboratory (ORNL). The temperature was 10°–100° with steps of 0.005° and analyzed by Rietveld controlled by a Lakeshore Bridge, while the magnetic field refinement using the GSAS software29. was generated by an Oxford-5 T superconducting magnet. The temperature-dependent diffraction profiles were Magnetic, specific heat, dielectric, and pyroelectric current measured at a wavelength of λ = 2.41 Å with the colli- measurements mation out-high intensity mode. The overall powder mass The magnetic susceptibility (χ) and magnetization (M) was 1.3 g.
Load more

Recommended publications
  • An Overview of Representational Analysis and Magnetic Space Groups
    Magnetic Symmetry: an overview of Representational Analysis and Magnetic Space groups Stuart Calder Neutron Scattering Division Oak Ridge National Laboratory ORNL is managed by UT-Battelle, LLC for the US Department of Energy Overview Aim: Introduce concepts and tools to describe and determine magnetic structures • Basic description of magnetic structures and propagation vector • What are the ways to describe magnetic structures properly and to access the underlying physics? – Representational analysis – Magnetic space groups (Shubnikov groups) 2 Magnetic Symmetry: an overview of Representational Analysis and Magnetic Space groups Brief History of magnetic structures • ~500 BC: Ferromagnetism documented Sinan, in Greece, India, used in China ~200 BC • 1932 Neel proposes antiferromagnetism • 1943: First neutron experiments come out of WW2 Manhatten project at ORNL • 1951: Antiferromagnetism measured in MnO and Ferrimagnetism in Fe3O4 at ORNL by Shull and Wollan with neutron scattering • 1950-60: Shubnikov and Bertaut develop methods for magnetic structure description • Present/Future: - Powerful and accessible experimental and software tools available - Spintronic devices and Quantum Information Science 3 Magnetic Symmetry: an overview of Representational Analysis and Magnetic Space groups Intrinsic magnetic moments (spins) in ions • Consider an ion with unpaired electrons • Hund’s rule: maximize S/J m=gJJ (rare earths) m=gsS (transtion metals) core 2+ Ni has a localized magnetic moment of 2µB Ni2+ • Magnetic moment (or spin) is a classical
    [Show full text]
  • Magnetic Point Groups
    GDR MEETICC Matériaux, Etats ElecTroniques, Interaction et Couplages non Conventionnels Winter school 4 – 10 February 2018, Banyuls-sur-Mer, France CRYSTALLOGRAPHIC and MAGNETIC STRUCTURES from NEUTRON DIFFRACTION: the POWER of SYMMETRIES (Lecture II) Béatrice GRENIER & Gwenaëlle ROUSSE UGA & CEA, INAC/MEM/MDN UPMC & Collège de France, Grenoble, France Paris, France GDR MEETICC Banyuls, Feb. 2018 Global outline (Lectures II, and III) II- Magnetic structures Description in terms of propagation vector: the various orderings, examples Description in terms of symmetry: Magnetic point groups: time reversal, the 122 magnetic point groups Magnetic lattices: translations and anti-translations, the 36 magnetic lattices Magnetic space groups = Shubnikov groups III- Determination of nucl. and mag. structures from neutron diffraction Nuclear and magnetic neutron diffraction: structure factors, extinction rules Examples in powder neutron diffraction Examples in single-crystal neutron diffraction Interest of magnetic structure determination ? Some material from: J. Rodriguez-Carvajal, L. Chapon and M. Perez-Mato was used to prepare Lectures II and III GDR MEETICC Crystallographic and Magnetic Structures / Neutron Diffraction, Béatrice GRENIER & Gwenaëlle ROUSSE 1 Banyuls, Feb. 2018 Interest of magnetic structure determination Methods and Computing Programs Multiferroics Superconductors GDR MEETICC Crystallographic and Magnetic Structures / Neutron Diffraction, Béatrice GRENIER & Gwenaëlle ROUSSE 2 Banyuls, Feb. 2018 Interest of magnetic structure determination Nano particles Multiferroics Computing Methods Manganites, charge ordering orbital ordering Heavy Fermions 3 GDR MEETICC Crystallographic and Magnetic Structures / Neutron Diffraction, Béatrice GRENIER & Gwenaëlle ROUSSE 3 Banyuls, Feb. 2018 1. What is a magnetic structure ? A crystallographic structure consists in a long-range order of atoms, described by a unit cell, a space group, and atomic positions of the asymmetry unit.
    [Show full text]
  • J. Phys. Condens. Matter
    Home Search Collections Journals About Contact us My IOPscience Magnetic superspace groups and symmetry constraints in incommensurate magnetic phases This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2012 J. Phys.: Condens. Matter 24 163201 (http://iopscience.iop.org/0953-8984/24/16/163201) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 147.231.126.111 The article was downloaded on 27/03/2012 at 10:54 Please note that terms and conditions apply. IOP PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER J. Phys.: Condens. Matter 24 (2012) 163201 (20pp) doi:10.1088/0953-8984/24/16/163201 TOPICAL REVIEW Magnetic superspace groups and symmetry constraints in incommensurate magnetic phases J M Perez-Mato1, J L Ribeiro2, V Petricek3 and M I Aroyo1 1 Departamento de F´ısica de la Materia Condensada, Facultad de Ciencia y Tecnolog´ıa, Universidad del Pa´ıs Vasco, UPV/EHU, Apartado 644, E-48080 Bilbao, Spain 2 Centro de F´ısica da Universidade do Minho, P-4710-057 Braga, Portugal 3 Institute of Physics, Academy of Sciences of the Czech Republic v.v.i., Na Slovance 2, CZ-18221 Praha 8, Czech Republic E-mail: [email protected] Received 11 November 2011, in final form 13 February 2012 Published 26 March 2012 Online at stacks.iop.org/JPhysCM/24/163201 Abstract Superspace symmetry has been for many years the standard approach for the analysis of non-magnetic modulated crystals because of its robust and efficient treatment of the structural constraints present in incommensurate phases.
    [Show full text]
  • Development of Symmetry Concepts for Aperiodic Crystals
    Symmetry 2014, 6, 171-188; doi:10.3390/sym6020171 OPEN ACCESS symmetry ISSN 2073-8994 www.mdpi.com/journal/symmetry Article Development of Symmetry Concepts for Aperiodic Crystals Ted Janssen Theoretical Physics, University of Nijmegen, Nijmegen 6525 ED, The Netherlands; E-Mail: [email protected]; Tel.: +31-24-39-72964 Received: 21 February 2014; in revised form: 18 March 2014 / Accepted: 26 March 2014 / Published: 31 March 2014 Abstract: An overview is given of the use of symmetry considerations for aperiodic crystals. Superspace groups were introduced in the seventies for the description of incommensurate modulated phases with one modulation vector. Later, these groups were also used for quasi-periodic crystals of arbitrary rank. Further extensions use time reversal and time translation operations on magnetic and electrodynamic systems. An alternative description of magnetic structures to that with symmetry groups, the Shubnikov groups, is using representations of space groups. The same can be done for aperiodic crystals. A discussion of the relation between the two approaches is given. Representations of space groups and superspace groups play a role in the study of physical properties. These, and generalizations of them, are discussed for aperiodic crystals. They are used, in particular, for the characterization of phase transitions between aperiodic crystal phases. Keywords: symmetry; aperiodic crystals; superspace 1. Introduction Symmetry plays an important role in the study of physical systems. A symmetry group is a group of transformations leaving both the structure of the physical system and the physical equations invariant. If new systems show new degrees of freedom, the symmetry groups usually have to be adapted.
    [Show full text]
  • A Van Der Waals Antiferromagnetic Topological Insulator with Weak Interlayer Magnetic Coupling
    ARTICLE https://doi.org/10.1038/s41467-019-13814-x OPEN A van der Waals antiferromagnetic topological insulator with weak interlayer magnetic coupling Chaowei Hu 1, Kyle N. Gordon2, Pengfei Liu3, Jinyu Liu1, Xiaoqing Zhou 2, Peipei Hao2, Dushyant Narayan2, Eve Emmanouilidou1, Hongyi Sun3, Yuntian Liu3, Harlan Brawer1, Arthur P. Ramirez4, Lei Ding 5, Huibo Cao 5, Qihang Liu3,6*, Dan Dessau 2,7* & Ni Ni 1* Magnetic topological insulators (TI) provide an important material platform to explore 1234567890():,; quantum phenomena such as quantized anomalous Hall effect and Majorana modes, etc. Their successful material realization is thus essential for our fundamental understanding and potential technical revolutions. By realizing a bulk van der Waals material MnBi4Te7 with alternating septuple [MnBi2Te4] and quintuple [Bi2Te3] layers, we show that it is ferro- magnetic in plane but antiferromagnetic along the c axis with an out-of-plane saturation field of ~0.22 T at 2 K. Our angle-resolved photoemission spectroscopy measurements and first- principles calculations further demonstrate that MnBi4Te7 is a Z2 antiferromagnetic TI with two types of surface states associated with the [MnBi2Te4] or [Bi2Te3] termination, respectively. Additionally, its superlattice nature may make various heterostructures of [MnBi2Te4] and [Bi2Te3] layers possible by exfoliation. Therefore, the low saturation field and the superlattice nature of MnBi4Te7 make it an ideal system to investigate rich emergent phenomena. 1 Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA. 2 Department of Physics, University of Colorado, Boulder, CO 80309, USA. 3 Shenzhen Institute for Quantum Science and Technology and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
    [Show full text]
  • 3 D$ Interactions and Spin-Induced Ferroelectricity in the Green Phase
    PHYSICAL REVIEW RESEARCH 2, 023271 (2020) Interplay of 4 f -3d interactions and spin-induced ferroelectricity in the green phase Gd2BaCuO5 Premakumar Yanda,1 I. V. Golosovsky,2 I. Mirebeau,3 N. V. Ter-Oganessian,4 Juan Rodríguez-Carvajal,5 and A. Sundaresan 1 1School of Advanced Materials and Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O. 560064, India 2National Research Center, Kurchatov Institute, B. P., Konstantinov Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia 3Université Paris-Saclay, CNRS, CEA, Laboratoire Léon Brillouin, 91191 Gif-sur-Yvette, France 4Institute of Physics, Southern Federal University, Rostov-on-Don 344090, Russia 5Institut Laue-Langevin, 71, Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France (Received 19 December 2019; revised manuscript received 31 March 2020; accepted 29 April 2020; published 3 June 2020) In most of the spin-induced multiferroics, the ferroelectricity is caused by inversion symmetry breaking by complex spin structures of the transition-metal ions. Here, we report the importance of interplay of 4 f -3d magnetic interactions in inducing ferroelectricity in the centrosymmetric (Pnma) green phase compound 3+ 2+ Gd2BaCuO5. With decreasing temperature, a long-range incommensurate ordering of both Gd and Cu spins at TN = 11.8 K occurs with the modulation vector k = (0, 0, g) and a lock-in transition to a strongly 1 noncollinear structure with kc = (0, 0, /2)atTloc ∼ 6 K. Both spin structures induce electric polarization consistent with the polar magnetic space groups Pm1 (α,0, g)ss and Paca21, respectively. Based on the symmetry analysis of magnetoelectric interactions, we suggest that the ferroelectricity in both commensurate and incommensurate phases is driven by a complex interplay of two-spins and single-spin contributions from magnetic ions located in noncentrosymmetric environments.
    [Show full text]
  • Site Mixing for Engineering Magnetic Topological Insulators
    PHYSICAL REVIEW X 11, 021033 (2021) Site Mixing for Engineering Magnetic Topological Insulators Yaohua Liu ,1,* Lin-Lin Wang,2 Qiang Zheng,3 Zengle Huang,4 Xiaoping Wang ,1 Miaofang Chi,5 Yan Wu , 1 † Bryan C. Chakoumakos ,1 Michael A. McGuire ,5 Brian C. Sales ,5 Weida Wu ,4 and Jiaqiang Yan 5,3, 1Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 2Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011, USA 3Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA 4Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA 5Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA (Received 1 September 2020; revised 9 December 2020; accepted 15 March 2021; published 12 May 2021) The van der Waals compound, MnBi2Te4, is the first intrinsic magnetic topological insulator, providing a materials platform for exploring exotic quantum phenomena such as the axion insulator state and the quantum anomalous Hall effect. However, intrinsic structural imperfections lead to bulk conductivity, and the roles of magnetic defects are still unknown. With higher concentrations of the same types of magnetic defects, the isostructural compound MnSb2Te4 is a better model system for a systematic investigation of the connections among magnetism, topology, and lattice defects. In this work, the impact of antisite defects on the magnetism and electronic structure is studied in MnSb2Te4. Mn-Sb site mixing leads to complex magnetic structures and tunes the interlayer magnetic coupling between antiferromagnetic and ferromag- netic. The detailed nonstoichiometry and site mixing of MnSb2Te4 crystals depend on the growth parameters, which can lead to ≈40% of Mn sites occupied by Sb and ≈15% of Sb sites by Mn in as-grown crystals.
    [Show full text]
  • Magnetic Phase Transitions and Symmetry Laurent C
    Magnetic phase transitions and symmetry Laurent C. Chapon Diamond Light Source, UK European School on Magnetism 1 Outline ● Will discuss exclusively the magnetically ordered state ● Different type of magnetic structures and how to describe them ● Magnetic symmetry, representation analysis, and magnetic space groups. ● Landau theory of phase transitions ● Symmetry breaking and types of domains European School on Magnetism 2 Description of magnetic structures Position of atom j in unit-cell l is given by: Rlj=Rl+rj where Rl is a pure lattice translation mlj rj Rl Direct lattice European School on Magnetism 3 Formalism of propagation vector For simplicity, in particular for wave-vector inside the BZ, one usually describe magnetic structures with Fourier components: Since mlj is a real vector, one must imposes the condition S-kj*=Skj Here Skj is a complex vector ! European School on Magnetism 4 Formalism of propagation vector -k +k Reciprocal lattice Reciprocal lattice (magnetic superlattices) European School on Magnetism 5 k=0 mlj Sk jexp 2 i kR l S k j k The magnetic structure may be described within the crystallographic unit cell Magnetic symmetry: conventional crystallography plus time reversal operator: crystallographic magnetic groups European School on Magnetism 6 K=1/2 r.l.v n(l) mlj Skj exp 2 ikRl Skj -1 k REAL Fourier coefficients = magnetic moments The magnetic symmetry may also be described using crystallographic magnetic space groups European School on Magnetism 7 K is inside the Brillouin Zone, amplitude modulation - k interior
    [Show full text]
  • Piezomagnetic Tensors Symmetries: an Unifying Tentative Approach Thibaut Weller, Giuseppe Geymonat
    Piezomagnetic tensors symmetries: an unifying tentative approach Thibaut Weller, Giuseppe Geymonat To cite this version: Thibaut Weller, Giuseppe Geymonat. Piezomagnetic tensors symmetries: an unifying tentative ap- proach. Configurational Mechanics, A. A. Balkema Publishers, 13p., 2004. hal-00797835 HAL Id: hal-00797835 https://hal.archives-ouvertes.fr/hal-00797835 Submitted on 7 Mar 2013 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Piezomagnetic tensors symmetries : an unifying tentative approach T. Weller, G. Geymonat Laboratoire de Mécanique et Génie Civil, UMR-CNRS 5508, c.c. 048, Université Montpellier II, Place Eugène Bataillon 34095 Montpellier Cedex 5, France [email protected] Abstract. Traditionally, one inquires as to what is the form of a physical property tensor invariant under the point group of a crystal. For example, one finds listings showing 16 distinct forms of the piezomagnetic tensor that can arise in a crystal. Alongside each of these 16 distinct forms is listed the point groups which give rise to that specific form (see Birss (1966) for example). This is a classification of the form of piezomagnetic tensors in crystals. We claim however that this classification is quite ambiguous in the sense that it hides the very difference between microscopic and macroscopic symmetries.
    [Show full text]
  • Geometry, Topology, and Response in Condensed Matter Systems by Dániel Varjas a Dissertation Submitted in Partial Satisfaction
    Geometry, topology, and response in condensed matter systems by D´anielVarjas A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Physics in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Joel E. Moore, Chair Professor Ashvin Vishwanath Professor Sayeef Salahuddin Summer 2016 Geometry, topology, and response in condensed matter systems Copyright 2016 by D´anielVarjas 1 Abstract Geometry, topology, and response in condensed matter systems by D´anielVarjas Doctor of Philosophy in Physics University of California, Berkeley Professor Joel E. Moore, Chair Topological order provides a new paradigm to view phases of matter. Unlike conven- tional symmetry breaking order, these states are not distinguished by different patterns of symmetry breaking, instead by their intricate mathematical structure, topology. By the bulk-boundary correspondence, the nontrivial topology of the bulk results in robust gap- less excitations on symmetry preserving surfaces. We utilize both of these views to study topological phases together with the analysis of their quantized physical responses to per- turbations. First we study the edge excitations of strongly interacting abelian fractional quantum Hall liquids on an infinite strip geometry. We use the infinite density matrix renormalization group method to numerically measure edge exponents in model systems, including subleading orders. Using analytic methods we derive a generalized Luttinger's theorem that relates momenta of edge excitations. Next we consider topological crystalline insulators protected by space group symme- try. After reviewing the general formalism, we present results about the quantization of the magnetoelectric response protected by orientation-reversing space group symmetries.
    [Show full text]
  • Nomenclature of Magnetic, Incommensurate, Composition- Changed Morphotropic, Polytype, Transient-Structural and Quasicrystalline Phases Undergoing Phase Transitions
    Nomenclature of magnetic, incommensurate, composition- changed morphotropic, polytype, transient-structural and quasicrystalline phases undergoing phase transitions. II. Report of an IUCr working group on Phase Transition Nomenclature Citation for published version (APA): Toledano, J. C., Berry, R. S., Brown, P. J., Glazer, A. M., Metselaar, R., Pandey, D., Perez-Mato, J. M., Roth, R. S., & Abrahams, S. C. (2001). Nomenclature of magnetic, incommensurate, composition-changed morphotropic, polytype, transient-structural and quasicrystalline phases undergoing phase transitions. II. Report of an IUCr working group on Phase Transition Nomenclature. Acta Crystallographica. Section A, Foundations of Crystallography, A57, 614-626. https://doi.org/10.1107/S0108767301006821 DOI: 10.1107/S0108767301006821 Document status and date: Published: 01/01/2001 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.
    [Show full text]
  • Arxiv:2010.10536V3 [Cond-Mat.Mes-Hall] 17 Jun 2021
    Topological correspondence between magnetic space group representations and subdimensions Adrien Bouhon,1, 2, ∗ Gunnar F. Lange,3 and Robert-Jan Slager3, y 1Nordic Institute for Theoretical Physics (NORDITA), Stockholm, Sweden 2Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 21 Uppsala, Sweden 3TCM Group, Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom (Dated: June 18, 2021) The past years have seen rapid progress in the classification of topological materials. These diag- nostical methods are increasingly getting explored in the pertinent context of magnetic structures. We report on a general class of electronic configurations within a set of anti-ferromagnetic-compatible space groups that are necessarily topological. Interestingly, we find a systematic correspondence between these anti-ferromagnetic phases to necessarily nontrivial topological ferro/ferrimagnetic counterparts that are readily obtained through physically motivated perturbations. Addressing the exhaustive list of magnetic space groups in which this mechanism occurs, we also verify its presence on planes in 3D systems that were deemed trivial in existing classification schemes. This leads to the formulation of the concept of subdimensional topologies, featuring non-triviality within part of the system that coexists with stable Weyl points away from these planes, thereby uncovering novel topological materials in the full 3D sense that have readily observable features in their bulk and surface spectrum. I. INTRODUCTION eigenvalues indicated schemes [34], that is symmetry indi- cators [35] and, very recently, topological quantum chem- With the advent of topological insulators (TIs) { istry [36]. gapped quantum matter having a topological entity by Already in the non-magnetic case the refined evalua- virtue of symmetry { the past years have seen a rein- tions resulted in new insights.
    [Show full text]