Quantum Criticality and Lifshitz Transition in the Ising System CeRu 2 Si 2 : Comparison with YbRh 2 Si 2
Quantum Criticality and Lifshitz Transition in the Ising System CeRu 2 Si 2 : Comparison with YbRh 2 Si 2
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DOI：
10.7566/jpsj.83.061002
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发表时间：
2013-11
影响因子：
1.7
通讯作者：
A. Pourret;D. Aoki;Mounir Boukahil;J. Brison;W. Knafo;G. Knebel;S. Raymond;M. Taupin;Y. Ōnuki;J. Flouquet
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文献类型：
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作者：
A. Pourret;D. Aoki;Mounir Boukahil;J. Brison;W. Knafo;G. Knebel;S. Raymond;M. Taupin;Y. Ōnuki;J. Flouquet
介绍了接近磁量子临界的原型重费米子化合物的热电功率（TEP）测量方法。TEP的高灵敏度技术是揭示费米表面不稳定性的独特工具，这里称为利夫希茨跃迁。第一个重点是Ising CeRu2Si2系列。用Rh掺杂CeRu2Si2，在纯化合物中观察到的一阶变磁跃迁和伪变磁之间产生了解耦。以自旋密度波临界为例，YbRh2Si2与CeRu2Si2相比，YbRh2Si2通常被视为局部量子临界的原型。到目前为止，对于表现出铁磁翅膀的铁磁材料，还没有出现在铁磁相和顺磁相之间保留费米面的简单情况。一个悬而未决的问题是这些多波段系统中利夫希茨跃迁对超导性的影响。
New thermoelectric power (TEP) measurements on prototype heavy-fermion compounds close to magnetic quantum criticality are presented. The highly sensitive technique of TEP is an unique tool to reveal Fermi surface instabilities, referred here as Lifshitz transitions. The first focus is on the Ising CeRu2Si2 series. Doping CeRu2Si2 with Rh produces a decoupling between the first order metamagnetic transition and the pseudo-metamagnetism observed in the pure compound. Comparison is made with the case of YbRh2Si2 which is often considered as the archetype of local quantum criticality by contrast to CeRu2Si2, taken as an example of spin-density wave criticality. Up to now for ferromagnetic materials showing ferromagnetic wings, no simple case appears where the Fermi surface is preserved between the ferromagnetic and paramagnetic phases. An open issue is the consequence of Lifshitz transitions on superconductivity in these multiband systems.