Pressure-induced changes of valence fluctuation in ß-YbAlB4 probed by x-ray absorption spectroscopy

被引：0

作者：

Sakaguchi, Yui ^{[1
]}

Ikeda, Shugo ^{[1
]}

Kawamura, Naomi ^{[2
]}

Mizumaki, Masaichiro ^{[2
]}

Kuga, Kentaro ^{[3
]}

Suzuki, Shintaro ^{[3
]}

Sone, Keita ^{[3
]}

Nakatsuji, Satoru ^{[3
,4
,5
,6
]}

Kobayashi, Hisao ^{[1
]}

机构：

[1] School of Material Science, University of Hyogo, Hyogo,678-1297, Japan

[2] Japan Synchrotron Radiation Research Institute, Hyogo,679-5198, Japan

[3] Institute for Solid State Physics, University of Tokyo, Kashiwa,277-8581, Japan

[4] Department of Physics, University of Tokyo, Tokyo,113-0033, Japan

[5] Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, Baltimore,MD,21218, United States

[6] Trans-Scale Quantum Science Institute, University of Tokyo, Tokyo,113-0033, Japan

来源：

Physical Review B | 2022年 / 105卷 / 15期

基金：

日本学术振兴会;

关键词：

Temperature distribution - Ytterbium - Quantum theory;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

We report detailed valence fluctuation phenomena in the unique quantum-critical compound ß-YbAlB4 under pressures and at low temperatures. We directly observed the drastic change in the pressure dependence of the mean Yb valence at about 3 GPa with no pressure-induced structural transition. Below 3 GPa, the anomaly in the temperature dependences of the mean Yb valence was observed at about 55 K under ambient pressure, corresponding to a previously observed reduced Kondo coherence temperature, and this temperature rapidly decreases to 22 K at 2.2 GPa, in contrast to the monotonous decrease of the high Kondo temperature (~250K at ambient pressure). The present results reveal that this reduced Kondo coherence temperature is responsible for the unconventional quantum critical behaviors in ß-YbAlB4. Above 3 GPa, it was found that the temperature dependence of the mean Yb valence exhibits a discontinuous change at low temperature (10.5 and 9 K under 4.8 and 5.5 GPa, respectively). © 2022 American Physical Society.

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