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arXiv · 1603.07973

The quantum ferromagnetic transition in a clean Kondo lattice is discontinuous

T. R. Kirkpatrick·D. Belitz
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Abstract

The Kondo-lattice model, which couples a lattice of localized magnetic moments to conduction electrons, is often used to describe heavy-fermion systems. Because of the interplay between Kondo physics and magnetic order it displays very complex behavior and is notoriously hard to solve. The ferromagnetic Kondo-lattice model, with a ferromagnetic coupling between the local moments, describes a phase transition from a paramagnetic phase to a ferromagnetic one as a function of either temperature or the ferromagnetic local-moment coupling. At zero temperature, this is a quantum phase transition that has received considerable attention. It has been theoretically described to be continuous, or second order. Here we show that this belief is mistaken; in the absence of quenched disorder the quantum phase transition is first order, in agreement with experiments, as is the corresponding transition in other metallic ferromagnets.

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T. R. Kirkpatrick, D. Belitz. 2016-03-29. The quantum ferromagnetic transition in a clean Kondo lattice is discontinuous. https://doi.org/10.1002/prop.201600028

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