Valence Fluctuations Revealed by Magnetic Field and Pressure Scans: Comparison with Experiments in YbXCu4 (X=In, Ag, Cd) and CeYIn5 (Y=Ir, Rh)
Valence Fluctuations Revealed by Magnetic Field and Pressure Scans: Comparison with Experiments in YbXCu4 (X=In, Ag, Cd) and CeYIn5 (Y=Ir, Rh)
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DOI：
10.1143/jpsj.78.104706
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发表时间：
2009-06
影响因子：
1.7
通讯作者：
S. Watanabe;A. Tsuruta;K. Miyake;J. Flouquet
中科院分区：
文献类型：
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作者：
S. Watanabe;A. Tsuruta;K. Miyake;J. Flouquet
讨论了磁场控制一阶价跃迁(FOVT)临界点的机制。我们证明了临界温度被磁场抑制为量子临界点(QCP)。这一结果解释了在Ce金属和YbInCu4中观察到的等结构FOVT的场依赖性。磁场扫描可以使系统重新进入临界价涨落区域。即使在中价材料中，QCP也是通过施加磁场来感应的，在磁场中，磁化率也会发散。场致QCP的驱动力是塞曼效应和近藤效应的共同作用，它与近藤温度产生了明显的能量标度。关键概念是FOVT对QCP的接近对于理解基于Ce和Yb的重费米子是至关重要的。这解释了CeYIn_5(Y=Ir，Rh)中特殊的磁性和输运响应以及YbXCu4中X=In的变磁相变。
The mechanism of how critical end points of the first-order valence transition (FOVT) are controlled by a magnetic field is discussed. We demonstrate that critical temperature is suppressed to be a quantum critical point (QCP) by a magnetic field. This results explain the field dependence of the isostructural FOVT observed in Ce metal and YbInCu 4 . Magnetic field scan can make the system reenter in a critical valence fluctuation region. Even in intermediate-valence materials, the QCP is induced by applying a magnetic field, at which magnetic susceptibility also diverges. The driving force of the field-induced QCP is shown to be a cooperative phenomenon of the Zeeman effect and the Kondo effect, which creates a distinct energy scale from the Kondo temperature. The key concept is that the closeness to the QCP of the FOVT is vital in understanding Ce- and Yb-based heavy-fermions. This explains the peculiar magnetic and transport responses in CeYIn 5 (Y=Ir, Rh) and metamagnetic transition in YbXCu 4 for X=In...