×

A classical \(\mathbb{S}^2\) spin system with discrete out-of-plane anisotropy: variational analysis at surface and vortex scalings. (English) Zbl 1512.49016

Summary: We consider a classical Heisenberg system of \(\mathbb{S}^2\) spins on a square lattice of spacing \(\varepsilon\). We introduce a magnetic anisotropy by constraining the out-of-plane component of each spin to take only finitely many values. Computing the \(\varGamma\)-limit of a suitable scaling of the energy functional as \(\varepsilon \to 0\) we prove that, in the continuum description, the system concentrates energy at the boundary of sets in which the out-of-plane component of the spin is constant. In a second step we analyze a different scaling of the energy and we prove that, in each of such phases, the energy can further concentrate on finitely many points corresponding to vortex-like singularities of the in-plane components of the spins.

MSC:

49J45 Methods involving semicontinuity and convergence; relaxation
49M25 Discrete approximations in optimal control
82B20 Lattice systems (Ising, dimer, Potts, etc.) and systems on graphs arising in equilibrium statistical mechanics
82D40 Statistical mechanics of magnetic materials
Full Text: DOI

References:

[1] Alberti, G.; Baldo, S.; Orlandi, G., Variational convergence for functionals of Ginzburg-Landau type, Indiana Univ. Math. J., 54, 1411-1472 (2005) · Zbl 1160.35013
[2] Alicandro, R.; Braides, A.; Cicalese, M., Phase and antiphase boundaries in binary discrete systems: a variational viewpoint, Netw. Heterog. Media, 1, 85-107 (2006) · Zbl 1131.49029
[3] Alicandro, R.; Braides, A.; Cicalese, M.; De Luca, L.; Piatnitski, A., Topological singularities in periodic media: Ginzburg-Landau and core-radius approaches, Arch. Ration. Mech. Anal., 243, 559-609 (2022) · Zbl 1481.35148
[4] Alicandro, R.; Cicalese, M., Variational analysis of the asymptotics of the XY model, Arch. Ration. Mech. Anal., 192, 501-536 (2009) · Zbl 1171.82004
[5] Alicandro, R.; Cicalese, M.; De Luca, L., Screw dislocations in periodic media: variational coarse graining of the discrete elastic energy, Nonlinear Anal. (2022)
[6] Alicandro, R.; Cicalese, M.; Ponsiglione, M., Variational equivalence between Ginzburg-Landau, XY spin systems and screw dislocations energies, Indiana Univ. Math. J., 60, 171-208 (2011) · Zbl 1251.49017
[7] Alicandro, R.; De Luca, L.; Garroni, A.; Ponsiglione, M., Metastability and dynamics of discrete topological singularities in two dimensions: A \(\Gamma \)-convergence approach, Arch. Ration. Mech. Anal., 214, 269-330 (2014) · Zbl 1305.82013
[8] Alicandro, R.; Focardi, M.; Gelli, M. S., Finite-difference approximation of energies in fracture mechanics, Ann. Sc. Norm. Super. Pisa Cl. Sci., 4, 671-709 (2001) · Zbl 1072.49020
[9] Ambrosio, L.; Fusco, N.; Pallara, D., Functions of Bounded Variation and Free Discontinuity Problems (2000), Clarendon Press: Clarendon Press Oxford · Zbl 0957.49001
[10] Bach, A.; Cicalese, M.; Kreutz, L.; Orlando, G., The antiferromagnetic XY model on the triangular lattice: Chirality transitions at the surface scaling, Calc. Var. Partial Differential Equations, 60, 149 (2021) · Zbl 1479.82005
[11] Bach, A.; Cicalese, M.; Kreutz, L.; Orlando, G., The antiferromagnetic XY model on the triangular lattice: topological singularities, Indiana Univ. Math. J. (2022), (in press) · Zbl 1510.53062
[12] Bethuel, F.; Brezis, H.; Hélein, F., Ginzburg-Landau Vortices (1994), Springer · Zbl 0802.35142
[13] Braides, A., \(( \Gamma \)-Convergence for Beginners. \( \Gamma \)-Convergence for Beginners, Oxford Lecture Series in Mathematics and its Applications, vol. 22 (2002), Oxford University Press: Oxford University Press Oxford) · Zbl 1198.49001
[14] Braides, A.; Cicalese, M.; Ruf, M., Continuum limit and stochastic homogenization of discrete ferromagnetic thin films, Anal. PDE, 11, 499-553 (2018) · Zbl 1379.49045
[15] Braides, A.; Cicalese, M.; Solombrino, F., Q-tensor continuum energies as limits of head-to-tail symmetric spins systems, SIAM J. Math. Anal., 47, 2832-2867 (2015) · Zbl 1321.49024
[16] Braides, A.; Cicalese. Interfaces, M., Modulated phases and textures in lattice systems, Arch. Ration. Mech. Anal., 223, 977-1017 (2017) · Zbl 1359.82006
[17] Cicalese, M.; Orlando, G.; Ruf, M., The \(N\)-clock model: Variational analysis for fast and slow divergence rates of \(N\). Preprint (2020), arXiv:2012.09548
[18] Cicalese, M.; Orlando, G.; Ruf, M., Coarse graining and large-\(N\) behaviour of the d-dimensional \(N\)-clock model, Interfaces Free Bound., 23, 323-351 (2021) · Zbl 1476.49019
[19] Cicalese, M.; Orlando, G.; Ruf, M., Emergence of concentration effects in the variational analysis of the \(N\)-clock model, Comm. Pure Appl. Math. (2022) · Zbl 07656133
[20] Dal Maso, G., (An Introduction to \(\Gamma \)-Convergence. An Introduction to \(\Gamma \)-Convergence, Progress in Nonlinear Differential Equations and their Applications, vol. 8 (1993), Birkhäuser Boston, Inc.: Birkhäuser Boston, Inc. Boston, MA) · Zbl 0816.49001
[21] De Luca, L.; Garroni, A.; Ponsiglione, M., \( \Gamma \)-Convergence analysis of systems of edge dislocations: the self energy regime, Arch. Ration. Mech. Anal., 206, 885-910 (2012) · Zbl 1366.74006
[22] De Luca, L.; Ponsiglione, M., Low energy configurations of topological singularities in two dimensions: a \(\Gamma \)-convergence analysis of dipoles, Commun. Contemp. Math., 22, Article 1950019 pp. (2020) · Zbl 1434.35200
[23] Gustafson, S.; Wang, Li., Co-rotational chiral magnetic skyrmions near harmonic maps, J. Funct. Anal., 4, Article 108867 pp. (2021) · Zbl 1454.35366
[24] Jerrard, R. L., Lower bounds for generalized Ginzburg-Landau functionals, SIAM J. Math. Anal., 30, 721-746 (1999) · Zbl 0928.35045
[25] Jerrard, R. L.; Soner, H. M., The Jacobian and the Ginzburg-Landau energy, Calc. Var. Partial Differential Equations, 14, 151-191 (2002) · Zbl 1034.35025
[26] Jerrard, R. L.; Soner, H. M., Limiting behavior of the Ginzburg-Landau functional, J. Funct. Anal., 192, 524-561 (2002) · Zbl 1028.49015
[27] Kurzke, M.; Spirn, D., Gamma limit of the nonself-dual Chern-Simons-Higgs energy, J. Funct. Anal., 255, 535-588 (2008) · Zbl 1158.81025
[28] Melcher, C., Chiral skyrmions in the plane, Proc. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci., 470, Article 20140394 pp. (2014) · Zbl 1371.81320
[29] Ponsiglione, M., Elastic energy stored in a crystal induced by screw dislocations: from discrete to continuous, SIAM J. Math. Anal., 39, 449-469 (2007) · Zbl 1135.74037
[30] Sandier, E., Lower bounds for the energy of unit vector fields and applications, J. Funct. Anal., 152, 379-403 (1998) · Zbl 0908.58004
[31] Sandier, E.; Serfaty, S., Vortices in the Magnetic Ginzburg-Landau Model (2008), Springer Science & Business Media · Zbl 1255.82072
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.