Spin-orbit induced noncubiccharge distribution in cubic ferromagnets. II. Tight-binding analysis

Article

关键词: TRANSITION-METAL IMPURITIES;    ELECTRIC-FIELD GRADIENT;    MAGNETOCRYSTALLINE ANISOTROPY;    MAGNETIC-ANISOTROPY;    SYSTEMS;    ALLOYS;    MOMENT;    FE;    CO;    NI;   

DOI  :  10.1103/PhysRevB.66.174402

来源: SCIE

【 摘 要 】

Using Monte Carlo and spin-dynamics methods, we have investigated the dynamic behavior of the classical, antiferromagnetic XY model on a triangular lattice with linear sizes Lless than or equal to300. The temporal evolutions of spin configurations were obtained by solving numerically the coupled equations of motion for each spin using fourth-order Suzuki-Trotter decompositions of exponential operators. From space- and time-displaced spin-spin correlation functions and their space-time Fourier transforms we obtained the dynamic structure factor S(q,w) for momentum q and frequency omega. Below T-KT (Kosterlitz-Thouless transition), both the in-plane (S-xx) and out-of-plane (S-zz) components of S(q,omega) exhibit very strong and sharp spin-wave peaks. Well above T-KT, S-xx and S-zz apparently display a central peak, and spin-wave signatures are still seen in S-zz. In addition, we also observed an almost dispersionless domain-wall peak at high omega below T-c (Ising transition), where long-range order appears in the staggered chirality. Above T-c, the domain-wall peak disappears for all q. The line shape of these peaks is captured reasonably well by a Lorentzian form. Using a dynamic finite-size scaling theory, we determined the dynamic critical exponent z=1.002(3). We found that our results demonstrate the consistency of the dynamic finite-size scaling theory for the characteristic frequency omega(m) and the dynamic structure factor S(q,omega) itself.

【 授权许可】

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