Quantum Valence Criticality as Origin of Unconventional Critical Phenomena

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 $\zeta 0.6$ giving rise to a huge enhancement of the Wilson ratio and the emergence of T-linear resistivity are explained in a unified way.

5 pages, 3 figures, to be published in Physical Review Letters

References in corpus (5)

• Signatures of valence fluctuations in CeCu2Si2 under high pressure
• Multiple energy scales at a quantum critical point
• Magnetic-Field Control of Quantum Critical Points of Valence Transition
• YbRh2Si2: Quantum tricritical behavior in itinerant electron systems
• Tricritical Phenomena at the Cerium $\gamma \to \alpha$ Transition

Cited by in corpus (4)

• Quantum critical state in a magnetic quasicrystal
• Roles of Critical Valence Fluctuations in Ce- and Yb-Based Heavy Fermion Metals
• New Universality Class of Quantum Criticality in Ce- and Yb-based Heavy Fermions
• T/B Scaling in beta-YbAlB4