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Tricritical behavior in itinerant quantum ferromagnets

D. Belitz·T. R. Kirkpatrick·Joerg Rollbuehler
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Abstract

It is shown that the peculiar features observed in the low-temperature phase diagrams of ZrZn_2, UGe_2, and MnSi can be understood in terms of a simple mean-field theory. The nature of the ferromagnetic transition changes from second order to first order at a tricritical point, and in a small external magnetic field surfaces of first-order transitions emerge which terminate in quantum critical points. This field dependence of the phase diagram follows directly from the existence of the tricritical point. The quantum critical behavior in a nonzero field is calculated exactly.

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BibTeXRIS

D. Belitz, T. R. Kirkpatrick, Joerg Rollbuehler. 2004-10-13. Tricritical behavior in itinerant quantum ferromagnets. https://doi.org/10.1103/physrevlett.94.247205

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