To examine the theory of quantum critical phenomena of valence fluctuations, we applied for the long-term proposal at SPring-8 by organizing experimental groups:
Experimental Examination of New Quantum Critical Phenomena of Critical Valence Fluctuations by X-ray Spectroscopy
Accurate measurement of valence of rare-earth ion in Yb, Ce , and Eu compounds has been performed in the extreme condition of low-temperature, high pressure, and strong magnetic field.
Beamline: BL39XU at SPring-8
Project No.: 0046
Leader: Shinji Watanabe
Period: 2012 October - 2015 September
As one of main results,
we discovered the critical point of the Yb-valence transition in the paramagnetic-metal phase in YbNi3Ga9 [1].
We also found the divergence of magnetic susceptibility at the critical point, which has been predicted by the theory of critical valence fluctuations [2].
[1] Pressure-Induced Valence Crossover and Novel Metamagnetic Behavior near the Antiferromagnetic Quantum Phase Transition of YbNi3Ga9
K. Matsubayashi, T. Hirayama, T. Yamashita, S. Ohara, N. Kawamura, M. Mizumaki, N. Ishimatsu, S. Watanabe, K. Kitagawa, and Y. Uwatoko: Phys. Rev. Lett. 114 (2015) 086401.
[2] S. Watanabe, A. Tsuruta, K. Miyake and J. Flouquet: Phys. Rev. Lett. 100 (2008) 236401.
For detail, see Research Project and Press Release.
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Last updated: May 18 2016