Roles of critical valence fluctuations in Ce- and Yb-based heavy fermion metals
Roles of critical valence fluctuations in Ce- and Yb-based heavy fermion metals
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DOI：
10.1088/0953-8984/23/9/094217
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发表时间：
2011-03
期刊：
影响因子：
--
通讯作者：
S. Watanabe;K. Miyake
中科院分区：
文献类型：
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作者：
S. Watanabe;K. Miyake
Ce 和 Yb 临界价波动的作用被讨论为在 Ce 和 Yb 基重费米子系统中观察到的几种异常的关键根源。该理论的最新发展表明，磁场是诱导一阶价态跃迁临界终点的有效控制参数。通过与CeIrIn5、YbAgCu4和YbIr2Zn20的对比，讨论了由该机制引起的超磁性和非费米液体行为。磁序和价态波动的相互作用为理解基于 Ce 和 Yb 的系统提供了一个关键概念。结果表明，通过增强的价态波动抑制磁序会导致磁转变点和价态交叉点在绝对零处重合，作为压力或磁场的函数。这种相互作用被证明可以以统一的方式解决 CeRhIn5 中的突出难题。通过调查 YbAuCu4、β-YbAlB4 和 YbRh2Si2 等有前景的材料，讨论了这一新阐明的机制的更广泛适用性。
The roles of critical valence fluctuations of Ce and Yb are discussed as a key origin of several anomalies observed in Ce- and Yb-based heavy fermion systems. Recent development of the theory has revealed that a magnetic field is an efficient control parameter to induce the critical end point of the first-order valence transition. Metamagnetism and non-Fermi liquid behavior caused by this mechanism are discussed by comparing favorably with CeIrIn5, YbAgCu4 and YbIr2Zn20. The interplay of the magnetic order and valence fluctuations offers a key concept for understanding Ce- and Yb-based systems. It is shown that suppression of the magnetic order by enhanced valence fluctuations gives rise to the coincidence of the magnetic-transition point and valence crossover point at absolute zero as a function of pressure or magnetic field. The interplay is shown to resolve the outstanding puzzle in CeRhIn5 in a unified way. The broader applicability of this newly clarified mechanism is discussed by surveying promising materials such as YbAuCu4, β-YbAlB4 and YbRh2Si2.