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Anomalous pinning fields in itinerant helical magnets: Screening of the quasiparticle interaction

¹Institute for Physical Science and Technology and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
²Department of Physics, Institute of Theoretical Science, and Materials Science Institute, University of Oregon, Eugene, Oregon 97403, USA

Phys. Rev. B 80, 220401(R) – Published 2 December, 2009

DOI: https://doi.org/10.1103/PhysRevB.80.220401

Abstract

The spin-orbit interaction strength $g_{so}$ in helical magnets determines both the pitch wave number $q$ and the critical field $H_{c 1}$ where the helix aligns with an external magnetic field. Within a standard Landau-Ginzburg-Wilson (LGW) theory, a determination of $g_{so}$ 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 helical fluctuations.

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References (27)

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Anomalous pinning fields in itinerant helical magnets: Screening of the quasiparticle interaction

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