摘要翻译:
我们给出了垂直各向异性超薄膜的二维海森堡模型的蒙特卡罗模拟结果。得到了一个完整的相图,作为各向异性和温度的函数,跨越了广泛的行为范围。我们讨论了我们的结果与不同超薄膜的实验结果的关系。我们观察并表征了一条自旋重定向跃迁线。这种从平面外条纹有序到平面内铁磁有序的转变在参数空间的有限区域中表现出顺磁间隙,正如实验所报道的那样。对于大的各向异性,观察到由低温条纹相直接转变为垂直磁化强度占优势的顺磁或四方相,这与实验结果也是一致的。我们还给出了无交换体系的相图,即具有纯偶极和各向异性相互作用的体系。在低温下,它表现出类似于铁磁情形的反铁磁相而不是条带相。在这种情况下还发现了自旋重定向跃迁。
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英文标题:
《The Spin Reorientation Transition and Phase Diagram of Ultrathin
Ferromagnetic Films》
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作者:
Marianela Carubelli, Orlando V. Billoni, Santiago Pighin, Sergio A.
Cannas, Daniel A. Stariolo, Francisco A. Tamarit
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最新提交年份:
2007
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分类信息:
一级分类:Physics 物理学
二级分类:Disordered Systems and Neural Networks 无序系统与
神经网络
分类描述:Glasses and spin glasses; properties of random, aperiodic and quasiperiodic systems; transport in disordered media; localization; phenomena mediated by defects and disorder; neural networks
眼镜和旋转眼镜;随机、非周期和准周期系统的性质;无序介质中的传输;本地化;由缺陷和无序介导的现象;神经网络
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一级分类:Physics 物理学
二级分类:Statistical Mechanics 统计力学
分类描述:Phase transitions, thermodynamics, field theory, non-equilibrium phenomena, renormalization group and scaling, integrable models, turbulence
相变,热力学,场论,非平衡现象,重整化群和标度,可积模型,湍流
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英文摘要:
We show results from Monte Carlo simulations of a two dimensional Heisenberg model for ultrathin films with perpendicular anisotropy. A complete phase diagram is obtained as a function of anisotropy and temperature, spanning a wide range of behavior. We discuss our results in relation with experimental findings in different ultrathin films. We observe and characterize a line of Spin Reorientation Transitions . This transition from out of plane stripe order to in plane ferromagnetic order presents a paramagnetic gap in between in a finite region in parameter space, as reported in experiments. For large anisotropies direct transitions from a low temperature stripe phase to a paramagnetic or tetragonal phase with dominant perpendicular magnetization is observed, also in agreement with experiments. We also show the phase diagram for a system without exchange, i.e. with pure dipolar and anisotropy interactions. It shows a similar behavior to the ferromagnetic case with antiferromagnetic instead of stripe phases at low temperatures. A Spin Reorientation Transition is also found in this case.
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PDF链接:
https://arxiv.org/pdf/712.2426