摘要翻译:
拓扑相空间断开是孤立各向异性自旋系统中的一种普遍现象。它从微观模型出发,没有现象学的现场障碍,为理解有限磁系统中铁磁性的出现提供了一个一般的框架。在这里,我们研究了与热浴接触的具有长程相互作用势的有限系统的相关性。我们表明,即使在这种情况下,感应磁反转时间在自旋数上也是指数大的,从而决定了(对任何实验观测时间)铁磁行为的{\It稳定}。此外,由微正则结果得到的磁反转时间的显式温度依赖关系与数值模拟结果符合得很好。此外,在低温下,解析地得到了一个简单而有启发意义的表达式,该表达式指示了许多物体系统的一个真实的能量屏障,即断开发生的拓扑能量阈值。
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英文标题:
《Magnetic Reversal Time in Open Long Range Systems》
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作者:
F.Borgonovi, G.L.Celardo, B. Goncalves, L. Spadafora
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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: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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一级分类:Physics 物理学
二级分类:Mesoscale and Nanoscale Physics 介观和纳米物理
分类描述:Semiconducting nanostructures: quantum dots, wires, and wells. Single electronics, spintronics, 2d electron gases, quantum Hall effect, nanotubes, graphene, plasmonic nanostructures
半导体纳米结构:量子点、线和阱。单电子学,自旋电子学,二维电子气,量子霍尔效应,纳米管,石墨烯,等离子纳米结构
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英文摘要:
Topological phase space disconnection has been recently found to be a general phenomenon in isolated anisotropic spin systems. It sets a general framework to understand the emergence of ferromagnetism in finite magnetic systems starting from microscopic models without phenomenological on-site barriers. Here we study its relevance for finite systems with long range interacting potential in contact with a thermal bath. We show that, even in this case, the induced magnetic reversal time is exponentially large in the number of spins, thus determining {\it stable} (to any experimental observation time) ferromagnetic behavior. Moreover, the explicit temperature dependence of the magnetic reversal time obtained from the microcanonical results, is found to be in good agreement with numerical simulations. Also, a simple and suggestive expression, indicating the Topological Energy Threshold at which the disconnection occurs, as a real energy barrier for many body systems, is obtained analytically for low temperature.
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PDF链接:
https://arxiv.org/pdf/710.3935