Anomalous Pinning Fields in Helical Magnets

ORAL

Abstract

The spin-orbit interaction strength $g_{\textrm{so}}$ in helical magnets determines both the pitch wave number $q$ and the critical field $H_{\textrm{c1}}$ where the helix aligns with an external magnetic field. Within a standard Landau-Ginzburg-Wilson (LGW) theory, a determination of $g_{\textrm{so}}$ in MnSi and FeGe from these two observables yields values that differ by a factor of $20$. This discrepancy is remedied by considering the fermionic theory underlying the LGW theory, and in particular the effects of screening on the effective electron-electron interaction that results from an exchange of helimagnons [1]. \\[4pt] $[1]$ T.R. Kirkpatrick and D. Belitz, Phys. Rev. B, in press.

*Supported by the NSF under grant Nos. DMR-09-01952, and DMR-09-01907.

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Authors

  • D. Belitz

    • Department of Physics, and Institute of Theoretical Science, University of Oregon, Eugene, OR 97403

  • T.R. Kirkpatrick

    • Institute for Physical Science and Technology, and Department of Physics, University of Maryland, College Park, MD 20742