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arXiv · 1211.1691

Spin Orbit Magnetism and Unconventional Superconductivity

Yi Zhang·Kevin S. Bedell
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Abstract

We find an exotic spin excitation in a magnetically ordered system with spin orbit magnetism in 2D, where the order parameter has a net spin current and no net magnetization. Starting from a Fermi liquid theory, similar to that for a weak ferromagnet, we show that this excitation emerges from an exotic magnetic Fermi liquid state that is protected by a generalized Pomeranchuck condition. We derive the propagating mode using the Landau kinetic equation, and find that the dispersion of the mode has a $\sqrt q$ behavior in leading order in 2D. We find an instability toward superconductivity induced by this exotic mode, and a further analysis based on the forward scattering sum rule strongly suggests that this superconductivity has p-wave pairing symmetry. We perform similar studies in the 3D case, with a slightly different magnetic system and find that the mode leads to a Lifshitz-like instability most likely toward an inhomogeneous magnetic state in one of the phases.

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Yi Zhang, Kevin S. Bedell. 2012-11-07. Spin Orbit Magnetism and Unconventional Superconductivity. https://doi.org/10.1103/physrevb.87.115134

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