Metallic quantum ferromagnets
Metallic quantum ferromagnets
复制标题
DOI：
10.1103/revmodphys.88.025006
复制
发表时间：
2016-05-31
影响因子：
44.1
通讯作者：
Kirkpatrick, T. R.
中科院分区：
文献类型：
--
作者：
Brando, M.;Belitz, D.;Kirkpatrick, T. R.
综述了金属铁磁体中的量子相变，讨论了实验和理论两个方面。这些QPT可以根据淬灭无序的存在和强度进行分类：干净的系统一般会显示出从铁磁到顺磁状态的不连续或一阶QPT，作为一些控制参数的函数，如理论预测的那样。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，从低温下的铁磁状态转变为不同类型的长程有序，例如反铁磁或自旋密度波状态。在其他材料中，人们怀疑它会转变为具有玻璃状自旋动力学的状态。该评论提供了一个全面的讨论，目前的理解，这些不同的过渡和实验与理论之间的关系。
An overview of quantum phase transitions (QPTs) in metallic ferromagnets, discussing both experimental and theoretical aspects, is given. 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 a ferromagnetic to a paramagnetic state 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 glasslike spin dynamics is suspected. The review provides a comprehensive discussion of the current understanding of these various transitions and of the relation between experiment and theory.