"Theory of Two-Magnon Raman Scattering in Iron Pnictides and Chalcogenides"

C-C Chen: C.J. Jia, A. F. Kemper, R. R. Singh; Physical Review Letters, 02/10/11.

Additional Authors: C.J. Jia, A. F. Kemper, R. R. Singh

Abstract:

Although the parent iron-based pnictides and chalcogenides are itinerant antiferromagnets, the use of local moment picture to understand their magnetic properties is still widespread. We study magnetic Raman scattering from a local moment perspective for various quantum spin models proposed for this new class of superconductors. These models vary greatly in the level of magnetic frustration and show a vastly different two-magnon Raman response. Light scattering by two-magnon excitations thus provides a robust and independent measure of the underlying spin interactions. In accord with other recent experiments, our results indicate that the amount of magnetic frustration in these systems may be small.