Magnetic Structure of Nanowires and Magnetostatic Interaction

2010 ◽  
Vol 168-169 ◽  
pp. 269-272 ◽  
Author(s):  
A.A. Ivanov ◽  
V.A. Orlov ◽  
N.N. Podolsky
Keyword(s):  
Domain Wall ◽  
Numerical Simulations ◽  
Magnetic Structure ◽  
Domain Structure ◽  
Ground State ◽  
Exchange Coupling ◽  
Anisotropy Axis ◽  
Induced Anisotropy ◽  
Magnetostatic Interaction ◽  
Stable Domain

The ground state magnetization of nanowires built of ferromagnetic crystallites is considered taking into account the magnetostatic interaction. The criterion of formation of domains is found. The thickness of a domain wall is calculated analytically and the results are compared with the numerical simulations. We show that when the exchange coupling between crystallites is absent its role is played by magnetostatics that ensures the existence of stable domain structure. The direction of the induced anisotropy axis is shown to be determined by the shape of crystallites.

scholarly journals Domain walls in 4d $$ \mathcal{N} $$ = 1 SYM

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Diego Delmastro ◽  
Jaume Gomis
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
Simons Theory ◽  
Partition Functions ◽  
Quantum Field Theories ◽  
Yang Mills ◽  
Stable Domain ◽  
Coxeter Number ◽  
Topological Quantum ◽  
Simply Connected

Abstract 4d$$ \mathcal{N} $$ N = 1 super Yang-Mills (SYM) with simply connected gauge group G has h gapped vacua arising from the spontaneously broken discrete R-symmetry, where h is the dual Coxeter number of G. Therefore, the theory admits stable domain walls interpolating between any two vacua, but it is a nonperturbative problem to determine the low energy theory on the domain wall. We put forward an explicit answer to this question for all the domain walls for G = SU(N), Sp(N), Spin(N) and G2, and for the minimal domain wall connecting neighboring vacua for arbitrary G. We propose that the domain wall theories support specific nontrivial topological quantum field theories (TQFTs), which include the Chern-Simons theory proposed long ago by Acharya-Vafa for SU(N). We provide nontrivial evidence for our proposals by exactly matching renormalization group invariant partition functions twisted by global symmetries of SYM computed in the ultraviolet with those computed in our proposed infrared TQFTs. A crucial element in this matching is constructing the Hilbert space of spin TQFTs, that is, theories that depend on the spin structure of spacetime and admit fermionic states — a subject we delve into in some detail.

scholarly journals Spatially modulated magnetic structure of EuS due to the tetragonal domain structure of SrTiO3

2017 ◽  
Vol 1 (7) ◽  
Author(s):  
Aaron J. Rosenberg ◽  
Ferhat Katmis ◽  
John R. Kirtley ◽  
Nuh Gedik ◽  
Jagadeesh S. Moodera ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Domain Structure

scholarly journals Investigation of a Structural Phase Transition and Magnetic Structure of Na2BaFe(VO4)2: A Triangular Magnetic Lattice with a Ferromagnetic Ground State

2017 ◽  
Vol 56 (24) ◽  
pp. 14842-14849 ◽  
Author(s):  
Liurukara D. Sanjeewa ◽  
Vasile O. Garlea ◽  
Michael A. McGuire ◽  
Matthias Frontzek ◽  
Colin D. McMillen ◽  
...  
Keyword(s):  
Phase Transition ◽  
Magnetic Structure ◽  
Structural Phase Transition ◽  
Ground State ◽  
Structural Phase ◽  
Ferromagnetic Ground State

μSR study of the ground-state magnetic structure in CeRh2Si2

2000 ◽  
Vol 289-290 ◽  
pp. 32-37 ◽  
Author(s):  
Y Yamamoto ◽  
S Kawarazaki ◽  
Y Miyako ◽  
K Nishiyama ◽  
K Nagamine
Keyword(s):  
Magnetic Structure ◽  
Ground State

scholarly journals f-Electron and Magnetic Ordering Effects in Nickelates LaNiO2 and NdNiO2: Remarkable Role of The Cuprate-Like 3dx2-y2 Band

2020 ◽  
Author(s):  
Jianwei Sun ◽  
Ruiqi Zhang ◽  
Christopher Lane ◽  
Bahadur Singh ◽  
Johannes Nokelainen ◽  
...  
Keyword(s):  
Ground State ◽  
Exchange Coupling ◽  
Density Functional ◽  
High Temperature Superconductivity ◽  
Parent Compound ◽  
Magnetic Ordering ◽  
Striking Similarity ◽  
Infinite Layer ◽  
Open Questions

Abstract Recent discovery of superconductivity in the doped infinite-layer nickelates has renewed interest in understanding the nature of high-temperature superconductivity more generally. The low-energy electronic structure of the parent compound NdNiO2, the role of electronic correlations in driving superconductivity, and the possible relationship betweeen the cuprates and the nickelates are still open questions. Here, by comparing LaNiO2 and NdNiO2 systematically within a parameter free density functional framework, all-electron first-principles framework, we reveal the role Nd 4f-electrons in shaping the ground state of pristine NdNiO2. Strong similarities are found between the electronic structures of LaNiO2 and NdNiO2, except for the effects of the 4f-electrons. Hybridization between the Nd 4f and Ni 3d orbitals is shown to significantly modify the Fermi surfaces of various magnetic states. In contrast, the competition between the magnetically ordered phases depends mainly on the gaps in the Ni dx2-y2 band, so that the ground state in LaNiO2 and NdNiO2 turns out to be striking similarity to that of the cuprates. The d - p band-splitting is found to be much larger while the intralayer 3d ion-exchange coupling is smaller in the nickelates compared to the cuprates. Our estimated value of the on-site Hubbard U is similar to that in the cuprates, but the value of the Hund's coupling JH is found to be sensitive to the Nd magnetic moment. The exchange coupling J in NdNiO2 is only half as large as in the curpates, which may explain why Tc in the nickelates is half as large as the cuprates.

scholarly journals Hidden magnetic order in plutonium dioxide nuclear fuel

2018 ◽  
Vol 20 (32) ◽  
pp. 20943-20951 ◽  
Author(s):  
James T. Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
Andrew S. Wills ◽  
David O. Scanlon ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Nuclear Fuel ◽  
Computational Methods ◽  
Ground State ◽  
Magnetic Order ◽  
Crystal Symmetry ◽  
Plutonium Dioxide

The magnetic structure of PuO2 has been investigated by computational methods. A hereto unknown longitudinal 3k AFM ground-state that retains Fm3̄m crystal symmetry has been identified.

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