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arXiv · 1009.5757

Quantum Valence Criticality as Origin of Unconventional Critical Phenomena

Shinji Watanabe·Kazumasa Miyake
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Abstract

It is shown that unconventional critical phenomena commonly observed in paramagnetic metals YbRh2Si2, YbRh2(Si0.95Ge0.05)2, and beta-YbAlB4 is naturally explained by the quantum criticality of Yb-valence fluctuations. We construct the mode coupling theory taking account of local correlation effects of f electrons and find that unconventional criticality is caused by the locality of the valence fluctuation mode. We show that measured low-temperature anomalies such as divergence of uniform spin susceptibility $χT^{-ζ)$ with $ζ~0.6$ giving rise to a huge enhancement of the Wilson ratio and the emergence of T-linear resistivity are explained in a unified way.

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Shinji Watanabe, Kazumasa Miyake. 2010-09-29. Quantum Valence Criticality as Origin of Unconventional Critical Phenomena. https://doi.org/10.1103/physrevlett.105.186403

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