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Kondo Breakdown and Hybridization Fluctuations in the Kondo-Heisenberg Lattice

I. Paul·C. Pepin·M. R. Norman
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Abstract

We study the deconfined quantum critical point of the Kondo-Heisenberg lattice in three dimensions using a fermionic representation for the localized spins. The mean-field phase diagram exhibits a zero temperature quantum critical point separating a spin liquid phase where the hybridization vanishes and a Kondo phase where it does not. Two solutions can be stabilized in the Kondo phase, namely a uniform hybridization when the band masses of the conduction electrons and the spinons have the same sign, and a modulated one when they have opposite sign. For the uniform case, we show that above a very small temperature scale, the critical fluctuations associated with the vanishing hybridization have dynamical exponent z=3, giving rise to a resistivity that has a T log T behavior. We also find that the specific heat coefficient diverges logarithmically in temperature, as observed in a number of heavy fermion metals.

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I. Paul, C. Pepin, M. R. Norman. 2006-10-30. Kondo Breakdown and Hybridization Fluctuations in the Kondo-Heisenberg Lattice. https://doi.org/10.1103/physrevlett.98.026402

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