CLARIFICATION OF QUANTUM PHENOMENA AND THEIR EFFECTS OF CRITICAL END POINT OF FIRST ORDER TRANSITION IN QUANTUM DEGENERATE SYSTEMS

量子简并系统中量子现象及其一阶跃迁临界终点效应的澄清

• 批准号: 21740240
• 负责人: WATANABE Shinji
• 金额: $ 2.91万
• 依托单位: Kyushu Institute of Technology (2011)Osaka University (2009-2010)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21740240/
• 关键词: 強相関系; 量子臨界現象; 強相関電子系; 価数転移; 量子臨界終点; 重い電子系; 1次相転移; 非フェルミ液体; 量子臨界価数ゆらぎ; Ce化合物; Yb化合物; 価数揺動; メタ磁性

It is shown theoretically that in strongly correlated electron systems, near the quantum critical end point where the critical end point of the first-order transition is suppressed to absolute zero, new quantum critical phenomena emerge. Near the quantum critical end point of the first-order valence transition, as temperature is decreased, uniform magnetic susceptibility and nuclear magnetic relaxation rate show divergence, resistivity shows a T-linear dependence, and electronic specific-heat coefficient shows logarithmic divergence. These results naturally explain unconventional quantum critical phenomena observed recently in paramagnetic-metal phases in Ce-and Yb-based heavy electron systems.

理论上表明，在强相关电子系统中，在一阶跃迁的临界终点被抑制到绝对零的量子临界终点附近，会出现新的量子临界现象。在一级价态跃迁的量子临界终点附近，随着温度降低，均匀磁化率和核磁弛豫率呈现发散性，电阻率呈现T线性依赖性，电子比热系数呈现对数发散性。这些结果自然地解释了最近在基于 Ce 和 Yb 的重电子系统中的顺磁性金属相中观察到的非常规量子临界现象。