Classical magnetic vortex liquid and large thermal Hall conductivity in frustrated magnets with bond-dependent interactions

AbstractRecently, the observation of large thermal Hall conductivities in correlated insulators with no apparent broken symmetry has generated immense interest and debates on the underlying ground states. Here, considering frustrated magnets with bond-dependent interactions, which are realized in the so-called Kitaev materials, we theoretically demonstrate that a large thermal Hall conductivity can originate from a classical ground state without any magnetic order. We discover a liquid state of magnetic vortices, which are inhomogeneous spin textures embedded in the background of polarized spins, under out-of-plane magnetic fields. In the classical regime, different configurations of vortices form an effectively degenerate manifold. We study the static and dynamical properties of the magnetic vortex liquid state at zero and finite temperatures. In particular, we show that the spin excitation spectrum resembles a continuum of nearly flat Chern bands, which ultimately leads to a large thermal Hall conductivity. Possible connections to experiments are discussed.

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The dynamics of magnetic vortices and skyrmions

10.1093/oso/9780198787075.003.0022 ◽

2017 ◽

Author(s):

R. Antos ◽

Y. Otani

Keyword(s):

Dynamic Properties ◽

Basic Research ◽

Small Region ◽

Magnetic Vortex ◽

Magnetic Domains ◽

Spin Configuration ◽

Magnetic Vortices ◽

Wall Structures ◽

Magnetic Elements ◽

Out Of Plane

This chapter argues that control of magnetic domains and domain wall structures is one of the most important issues from the viewpoint of both applied and basic research in magnetism. Its discussion is however limited to static and dynamic properties of magnetic vortex structures. It has been revealed both theoretically and experimentally that for particular ranges of dimensions of cylindrical and other magnetic elements, a curling in-plane spin configuration is energetically favored, with a small region of the out-of-plane magnetization appearing at the core of the vortex. Such a system, which is sometimes referred to as a magnetic soliton, is characterized by two binary properties: A chirality and a polarity, each of which suggests an independent bit of information in future high-density nonvolatile recording media.

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QUANTUM MAGNETIC VORTICES AT FINITE TEMPERATURE IN (3 + 1)-D

Modern Physics Letters A ◽

10.1142/s0217732300000712 ◽

2000 ◽

Vol 15 (11n12) ◽

pp. 731-735

Author(s):

E. C. MARINO ◽

D. G. G. SASAKI

Keyword(s):

Correlation Function ◽

Correlation Functions ◽

Large Distance ◽

Finite Temperature ◽

Higgs Model ◽

Magnetic Vortex ◽

Zero Temperature ◽

Magnetic Vortices ◽

Vortex Lines ◽

Distance Behavior

We study the effect of a finite temperature on the correlation function of quantum magnetic vortex lines in the framework of the (3 + 1)-dimensional Abelian Higgs model. The vortex energy is inferred from the large distance behavior of these correlation functions. For large straight vortices of length L, we obtain that the energy is proportional to TL2 differently from the zero temperature result which is proportional to L. The case of closed strings is also analyzed. For T = 0, we evaluate the correlation function and energy of a large ring. Finite closed vortices do not exist as genuine excitations for any temperature.

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Anomalous Magnetization Behavior in the Vortex Liquid State in Bi2Sr2CaCu2O8+δ

Advances in Superconductivity XII ◽

10.1007/978-4-431-66877-0_123 ◽

2000 ◽

pp. 413-415 ◽

Cited By ~ 1

Author(s):

Kazuhiro Kimura ◽

Ryo Koshida ◽

Satoru Okayasu ◽

Masao Sataka ◽

Yukio Kazumata ◽

...

Keyword(s):

Liquid State ◽

Vortex Liquid ◽

Magnetization Behavior

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Erratum: “Laboratory studies of magnetic vortices. II. Helicity reversal during reflection of a magnetic vortex at a conducting boundary” [Phys. Plasmas 6, 3217 (1999)]

Physics of Plasmas ◽

10.1063/1.873774 ◽

1999 ◽

Vol 6 (12) ◽

pp. 4799-4799

Author(s):

R. L. Stenzel ◽

J. M. Urrutia ◽

M. C. Griskey

Keyword(s):

Magnetic Vortex ◽

Laboratory Studies ◽

Magnetic Vortices

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Thickness-dependent magnetic order in CrI3 single crystals

Scientific Reports ◽

10.1038/s41598-019-50000-x ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 7

Author(s):

Yu Liu ◽

Lijun Wu ◽

Xiao Tong ◽

Jun Li ◽

Jing Tao ◽

...

Keyword(s):

Domain Walls ◽

Magnetic Order ◽

Magnetic Transition ◽

Mean Field ◽

Magnetic Domain ◽

Crystal Thickness ◽

Range Magnetic Order ◽

Plane Field ◽

Out Of Plane ◽

Magnetic Domain Walls

Abstract Two-dimensional (2D) materials with intrinsic ferromagnetism provide unique opportunity to engineer new functionalities in nano-spintronics. One such material is CrI3, showing long-range magnetic order in monolayer with the Curie temperature (Tc) of 45 K. Here we study detailed evolution of magnetic transition and magnetic critical properties in response to systematic reduction in crystal thickness down to 50 nm. Bulk Tc of 61 K is gradually suppressed to 57 K, however, the satellite transition at T * = 45 K is observed layer-independent at fixed magnetic field of 1 kOe. The origin of T * is proposed to be a crossover from pinning to depinning of magnetic domain walls. The reduction of thickness facilitates a field-driven metamagnetic transition around 20 kOe with out-of-plane field, in contrast to the continuous changes with in-plane field. The critical analysis around Tc elucidates the mean-field type interactions in microscale-thick CrI3.

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Stiffness in vortex—like structures due to chirality-domains within a coupled helical rare-earth superlattice

Scientific Reports ◽

10.1038/srep19315 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 5

Author(s):

Amitesh Paul

Keyword(s):

Rare Earth ◽

Domain Walls ◽

Topological Defects ◽

Magnetic Ordering ◽

Direct Consequence ◽

Magnetic Vortex ◽

Range Magnetic Order ◽

Wide Range ◽

Out Of Plane ◽

The Stability

Abstract Vortex domain walls poses chirality or ‘handedness’ which can be exploited to act as memory units by changing their polarity with electric field or driving/manupulating the vortex itself by electric currents in multiferroics. Recently, domain walls formed by one dimensional array of vortex—like structures have been theoretically predicted to exist in disordered rare-earth helical magnets with topological defects. Here, in this report, we have used a combination of two rare-earth metals, e.g."Equation missing" superlattice that leads to long range magnetic order despite their competing anisotropies along the out-of-plane (Er) and in-plane (Tb) directions. Probing the vertically correlated magnetic structures by off-specular polarized neutron scattering we confirm the existence of such magnetic vortex—like domains associated with magnetic helical ordering within the Er layers. The vortex—like structures are predicted to have opposite chirality, side—by—side and are fairly unaffected by the introduction of magnetic ordering between the interfacial Tb layers and also with the increase in magnetic field which is a direct consequence of screening of the vorticity in the system due to a helical background. Overall, the stability of these vortices over a wide range of temperatures, fields and interfacial coupling, opens up the opportunity for fundamental chiral spintronics in unconventional systems.

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