Concept

Défaut topologique

Publications associées (294)

Metastable skyrmion lattices governed by magnetic disorder and anisotropy in beta-Mn-type chiral magnets

Magnetic skyrmions are vortexlike topological spin textures often observed in structurally chiral magnets with Dzyaloshinskii-Moriya interaction. Among them, Co-Zn-Mn alloys with a beta-Mn-type chiral structure host skyrmions above room temperature. In thi ...

AMER PHYSICAL SOC2020

Direct Observation of the Statics and Dynamics of Emergent Magnetic Monopoles in a Chiral Magnet

Henrik Moodysson Rønnow, Jonathan White

In the three-dimensional (3D) Heisenberg model, topological point defects known as spin hedgehogs behave as emergent magnetic monopoles, i.e., quantized sources and sinks of gauge fields that couple strongly to conduction electrons, and cause unconventiona ...

AMER PHYSICAL SOC2020

Magnon Modes of Microstates and Microwave-Induced Avalanche in Kagome Artificial Spin Ice with Topological Defects

Dirk Grundler, Vinayak Shantaram Bhat

We investigate spin dynamics of microstates in artificial spin ice (ASI) in Ni81Fe19 nanomagnets arranged in an interconnected kagome lattice using microfocus Brillouin light scattering, broadband ferromagnetic resonance, magnetic force microscopy, x-ray p ...

2020

Oxidation States, Thouless' Pumps, and Nontrivial Ionic Transport in Nonstoichiometric Electrolytes

Federico Grasselli

Thouless' quantization of adiabatic particle transport permits one to associate an integer topological charge with each atom of an electronically gapped material. If these charges are additive and independent of atomic positions, they provide a rigorous de ...

2020

How to weave a perfect sphere with curved strips

Mark Pauly, Tian Chen, Yingying Ren

Triaxial weaving, a craft technique that enables the generation of surfaces with tri-directional arrays of initially straight elastic strips, has long been loved by basket makers and artists seeking a combination of practical and aesthetically-pleasing str ...

American Physical Society2020

Topological Fermi-arc surface resonances in bcc iron

Oleg Yazyev, Daniel Gosalbez Martinez, Gabriel Albert Autes

The topological classification of matter has been extended to include semimetallic phases characterized by the presence of topologically protected band degeneracies. In Weyl semimetals, the foundational gapless topological phase, chiral degeneracies are is ...

AMER PHYSICAL SOC2020

In situ control of the helical and skyrmion phases in Cu2OSeO3 using high-pressure helium gas up to 5 kbar

Henrik Moodysson Rønnow, Arnaud Magrez, Ivica Zivkovic, Jonathan White

We report a small-angle neutron scattering study of the helical and skyrmion lattice order in single-crystal Cu2OSeO3 under quasihydrostatic helium gas pressures up to 5 kbar. By using helium gas as the pressure-transmitting medium (PTM) we ensure pressure ...

AMER PHYSICAL SOC2020

Influence of Minor Cr Additions on Crystal Growth in Rapidly Solidified Al-20Zn Alloys

Michel Rappaz

It has been discovered quite recently that Icosahedral Short-Range Order (ISRO) of atoms in the liquid phase of metallic alloys surrounding some trace elements added to the melt can influence both the nucleation and growth of the primary phase. In this wor ...

2020

Hermitian formulation of multiple scattering induced topological phases in metamaterial crystals

Romain Christophe Rémy Fleury, Nadège Sihame Kaïna

In this article we develop an analog to the SSH model in tight-binding chains of resonators and an innovative Hermitian matrix formulation to describe the topological phases induced by multiple scattering at subwavelength scales in one-dimensional structur ...

2020

Room-temperature skyrmion phase in bulk Cu2OSeO3 under high pressures

Helmuth Berger

A skyrmion state in a noncentrosymmetric helimagnet displays topologically protected spin textures with profound technological implications for high-density information storage, ultrafast spintronics, and effective microwave devices. Usually, its equilibri ...

2020

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