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The strongly enhanced magnetic excitations near the quantum critical point of Cr$_{1-x}$V$_x$ and why strong exchange enhancement need not imply heavy fermion behavior

S. M. Hayden·R. Doubble·G. Aeppli·T. G. Perring·E. Fawcett
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Abstract

Inelastic neutron scattering reveals strong spin fluctuations with energies as high as 0.4eV in the nearly antiferromagnetic metal Cr$_{0.95}$V$_{0.05}$. The magnetic response is well described by a modified Millis-Monien-Pines function. From the low-energy response, we deduce a large exchange enhancement, more than an order of magnitude larger than the corresponding enhancement of the low-temperature electronic heat capacity $γT$. A scaling relationship between $γ$ and the inverse of the wavevector- averaged spin relaxation rate $Γ_{\text{ave}}$ is demonstrated for a number of magnetically correlated metals

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S. M. Hayden, R. Doubble, G. Aeppli, T. G. Perring, E. Fawcett. 1999-11-26. The strongly enhanced magnetic excitations near the quantum critical point of Cr$_{1-x}$V$_x$ and why strong exchange enhancement need not imply heavy fermion behavior. https://doi.org/10.1103/physrevlett.84.999

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