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arXiv · 1108.5227

Kondo destruction and valence fluctuations in an Anderson model

J. H. Pixley·Stefan Kirchner·Kevin Ingersent·Qimiao Si
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Abstract

Unconventional quantum criticality in heavy-fermion systems has been extensively analyzed in terms of a critical destruction of the Kondo effect. Motivated by a recent demonstration of quantum criticality in a mixed-valent heavy-fermion system, \beta-YbAlB4, we study a particle-hole-asymmetric Anderson impurity model with a pseudogapped density of states. We demonstrate Kondo destruction at a mixed-valent quantum critical point, where a collapsing Kondo energy scale is accompanied by a singular charge-fluctuation spectrum. Both spin and charge responses scale with energy over temperature (\omega/T) and magnetic field over temperature (H/T). Implications for unconventional quantum criticality in mixed-valence heavy fermions are discussed.

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J. H. Pixley, Stefan Kirchner, Kevin Ingersent, Qimiao Si. 2011-08-26. Kondo destruction and valence fluctuations in an Anderson model. https://doi.org/10.1103/physrevlett.109.086403

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