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arXiv 1502.02898cond-mat.str-el
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金属量子铁磁体

Metallic Quantum Ferromagnets

M. Brando, D. Belitz, F. M. Grosche, T. R. Kirkpatrick

摘要:

本文综述了金属铁磁体中的量子相变(QPT)问题,讨论了实验和理论两个方面。这些QPT可以根据淬火无序的存在和强度进行分类:如理论所预测的,清洁系统一般显示出从铁磁态到顺磁态的不连续或一阶QPT。无序系统要复杂得多,这取决于无序强度和与QPT的距离。在许多无序材料中,QPT是连续的,或者是二阶的,并且格里菲斯相效应与过渡附近的QPT奇异性共存。在其他系统中,从低温下的铁磁态到另一种类型的长程序的转变,例如反铁磁态或自旋密度波态。在其他材料中,人们怀疑它会转变成类似玻璃的自旋动力学状态。该评论提供了一个全面的讨论,目前的理解,这些不同的过渡,实验和理论发展之间的关系。

英文摘要:

This review gives an overview of the quantum phase transition (QPT) problem in metallic ferromagnets, discussing both experimental and theoretical aspects. These QPTs can be classified with respect to the presence and strength of quenched disorder: Clean systems generically show a discontinuous, or first-order, QPT from the ferromagnetic state to a paramagnetic one as a function of some control parameter, as predicted by theory. Disordered systems are much more complicated, depending on the disorder strength and the distance from the QPT. In many disordered materials the QPT is continuous, or second order, and Griffiths-phase effects coexist with QPT singularities near the transition. In other systems the transition from the ferromagnetic state at low temperatures is to a different type of long-range order, such as an antiferromagnetic or a spin-density-wave state. In still other materials a transition to a state with glass-like spin dynamics is suspected. The review provides a comprehensive discussion of the current understanding of these various transitions, and of the relation between experimental and theoretical developments.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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