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arXiv · 1309.7047

Anomalous Fermi liquid phase in metallic Skyrmion crystals

Haruki Watanabe·S. A. Parameswaran·S. Raghu·Ashvin Vishwanath
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Abstract

In non-centrosymmetric crystals such as MnSi, magnetic order can take the form of a skyrmion crystal (SkX) . In this phase, conduction electrons coupled to the local magnetic moments acquire a Berry's phase, leading to an emergent electromagnetism. Motivated by experimental reports of a non-Fermi liquid phase in MnSi, in which resistivity is observed to scale as $Δρ\sim T^{3/2}$, here we examine the effect of coupling phonons of an incommensurate SkX to electrons. Despite the formal similarity to a system consisting of a Fermi surface coupled to an electromagnetic field, the Berry phase fluctuations do not lead to non-Fermi liquid behavior. Instead, we propose a different mechanism in which electrons scatter off columnar fluctuation in a three-dimensional SkX. When the effects of lattice induced anisotropy are neglected, these fluctuations are ultra-soft and induce an `anomalous Fermi liquid' in which Landau quasiparticles survive but with an anomalous $Δρ(T)\sim T^{7/4}$ resistivity perpendicular to the columns, and a Fermi liquid resistivity along them.

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Haruki Watanabe, S. A. Parameswaran, S. Raghu, Ashvin Vishwanath. 2014-07-30. Anomalous Fermi liquid phase in metallic Skyrmion crystals. https://doi.org/10.1103/physrevb.90.045145

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