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Hidden Quantum Critical Point in a Ferromagnetic Superconductor

Debanand Sa
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Abstract

We consider a coexistence phase of both Ferromagnetism and superconductivity and solve the self-consistent mean-field equations at zero temperature. The superconducting gap is shown to vanish at the Stoner point whereas the magnetization doesn't. This indicates that the para-Ferro quantum critical point becomes a hidden critical point. The effective mass in such a phase gets enhanced whereas the spin wave stiffness is reduced as compared to the pure FM phase. The spin wave stiffness remains finite even at the para-Ferro quantum critical point.

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Debanand Sa. 2002-09-10. Hidden Quantum Critical Point in a Ferromagnetic Superconductor. https://doi.org/10.1103/physrevb.66.140505

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