Visualization of large-scale charged domain Walls in hexagonal manganites

2021 ◽  
Vol 118 (7) ◽  
pp. 072901
Author(s):  
Fei Fan ◽  
Ziyan Gao ◽  
Louis Ponet ◽  
Jing Wang ◽  
Houbing Huang ◽  
...  
Keyword(s):  
Large Scale ◽  
Domain Walls ◽  
Hexagonal Manganites

scholarly journals Intrinsic and extrinsic conduction contributions at nominally neutral domain walls in hexagonal manganites

2020 ◽  
Vol 116 (26) ◽  
pp. 262903
Author(s):  
J. Schultheiß ◽  
J. Schaab ◽  
D. R. Småbråten ◽  
S. H. Skjærvø ◽  
E. Bourret ◽  
...  
Keyword(s):  
Domain Walls ◽  
Hexagonal Manganites

scholarly journals Measuring Ferroelectric Order Parameters at Domain Walls and Vortices in Hexagonal Manganites with Atomic Resolution STEM

2017 ◽  
Vol 23 (S1) ◽  
pp. 1636-1637
Author(s):  
Megan E. Holtz ◽  
Konstantin Shapovalov ◽  
Julia A. Mundy ◽  
Celesta S. Chang ◽  
Dennis Meier ◽  
...  
Keyword(s):  
Domain Walls ◽  
Order Parameters ◽  
Atomic Resolution ◽  
Hexagonal Manganites ◽  
Ferroelectric Order

First-Principles Studies of Structural Domain Walls

Domain Walls ◽  
2020 ◽  
pp. 36-75
Author(s):  
J. Íñiguez
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Large Scale ◽  
Domain Walls ◽  
Perovskite Oxides ◽  
Added Value ◽  
Structural Domain ◽  
Simulation Methods ◽  
Functional Theory ◽  
Large Scale Simulations

This chapter discusses representative first-principles studies of structural domain walls in ferroics, focusing on the compounds that have received most attention by the simulations community so far: perovskite oxides. It describes in some detail a reduced number of case studies that come handy to illustrate different effects and to highlight the added value of the first-principles investigations. As regards the simulation methods, the chapter focuses on applications of density functional theory (DFT), typically employing an approximation for an effective treatment of ionic cores. A discussion on the application to domain-wall problems of first-principles-based methods for large-scale simulations of ferroelectrics and ferroelastics is also included. Finally, this chapter briefly on the opportunities and challenges for first-principles research in this field.

scholarly journals Nonlocal Quantum Effects in Cosmology

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Yurii V. Dumin
Keyword(s):  
Early Universe ◽  
Large Scale ◽  
Domain Walls ◽  
Early Stage ◽  
Topological Defects ◽  
Anomalous Behavior ◽  
Quantum Nonlocality ◽  
Ultracold Gases ◽  
Laboratory Studies ◽  
Microwave Background

Since it is commonly believed that the observed large-scale structure of the universe is an imprint of quantum fluctuations existing at the very early stage of its evolution, it is reasonable to pose the question: do the effects of quantum nonlocality, which are well established now by the laboratory studies, manifest themselves also in the early universe? We try to answer this question by utilizing the results of a few experiments, namely, with the superconducting multi-Josephson-junction loops and the ultracold gases in periodic potentials. Employing a close analogy between the above-mentioned setups and the simplest one-dimensional Friedmann-Robertson-Walker cosmological model, we show that the specific nonlocal correlations revealed in the laboratory studies might be of considerable importance also in treating the strongly nonequilibrium phase transitions of Higgs fields in the early universe. Particularly, they should substantially reduce the number of topological defects (e.g., domain walls) expected due to independent establishment of the new phases in the remote spatial regions. This gives us a hint on resolving a long-standing problem of the excessive concentration of topological defects, inconsistent with observational constraints. The same effect may be also relevant to the recent problem of the anomalous behavior of cosmic microwave background fluctuations at large angular scales.

DYNAMICS OF FERROMAGNETIC WALLS: GRAVITATIONAL PROPERTIES

2005 ◽  
Vol 14 (03n04) ◽  
pp. 521-541 ◽  
Author(s):  
L. CAMPANELLI ◽  
P. CEA ◽  
G. L. FOGLI ◽  
L. TEDESCO
Keyword(s):  
Domain Wall ◽  
Large Scale ◽  
Domain Walls ◽  
Background Radiation ◽  
Ideal Gas ◽  
Microwave Background ◽  
Electroweak Phase Transition ◽  
Microwave Background Radiation ◽  
The Universe ◽  
Negligible Contribution

We discuss a new mechanism which allows domain walls produced during the primordial electroweak phase transition. We show that the effective surface tension of these domain walls can be made vanishingly small due to a peculiar magnetic condensation induced by fermion zero modes localized on the wall. We find that in the perfect gas approximation the domain wall network behaves like a radiation gas. We consider the recent high-red shift supernova data and we find that the corresponding Hubble diagram is compatible with the presence in the Universe of an ideal gas of ferromagnetic domain walls. We show that our domain wall gas induces a completely negligible contribution to the large-scale anisotropy of the microwave background radiation.

scholarly journals Walker-like domain wall breakdown in layered antiferromagnets driven by staggered spin–orbit fields

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Rubén M. Otxoa ◽  
P. E. Roy ◽  
R. Rama-Eiroa ◽  
J. Godinho ◽  
K. Y. Guslienko ◽  
...  
Keyword(s):  
Domain Wall ◽  
Large Scale ◽  
Domain Walls ◽  
Spin Dynamics ◽  
Continuum Theory ◽  
Dynamical Regime ◽  
Spin Orbit ◽  
Translational Invariance ◽  
Domain Structures ◽  
Dynamics Simulations

Abstract Within linear continuum theory, no magnetic texture can propagate faster than the maximum group velocity of the spin waves. Here, by atomistic spin dynamics simulations and supported by analytical theory, we report that a strongly non-linear transient regime due to the appearance of additional magnetic textures results in the breaking of the Lorentz translational invariance. This dynamical regime is akin to domain wall Walker-breakdown in ferromagnets and involves the nucleation of an antiferromagnetic domain wall pair. While one of the nucleated domain walls is accelerated beyond the magnonic limit, the remaining pair remains static. Under large spin–orbit fields, a cascade of multiple generation and recombination of domain walls are obtained. This result may clarify recent experiments on current pulse induced shattering of large domain structures into small fragmented domains and the subsequent slow recreation of large-scale domains.

scholarly journals Phase engineering in oxides by interfaces

2012 ◽  
Vol 370 (1977) ◽  
pp. 4972-4988 ◽  
Author(s):  
Manfred Fiebig
Keyword(s):  
Domain Walls ◽  
Second Harmonic ◽  
Piezoresponse Force Microscopy ◽  
Bulk Crystals ◽  
Oxide Interface ◽  
Force Microscopy ◽  
Hexagonal Manganites ◽  
Phase Engineering ◽  
Protected Domain ◽  
Antiferromagnetic Domains

Optical second harmonic generation and piezoresponse force microscopy are used to investigate manifestations of ordered states directly related to the presence of an oxide interface. Three examples, each with a very different scope, are reviewed in order to highlight the richness of interface-related phenomena in oxides. (i) The orbital states involved in the emergence of an interfacial conducting state in LaAlO 3 /SrTiO 3 heterostructures are investigated, which reveal a surprising decoupling of orbital and transport properties; (ii) the distribution of ferroelectric and antiferromagnetic domains in epitaxial films of the multiferroic hexagonal manganites is investigated, which reveals striking differences to the corresponding bulk crystals; and (iii) the distribution of trimerization–polarization domains in the hexagonal manganites is investigated, which reveals the presence of topologically protected domain walls with properties different from the bulk.

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