Frontiers in Physics (Sep 2020)
Quasiclassical Theory of C4-Symmetric Magnetic Order in Disordered Multiband Metals
Abstract
Recent experimental studies performed in the normal state of iron-based superconductors have discovered the existence of the C4-symmetric (tetragonal) itinerant magnetic state. This state can be described as a spin density wave with two distinct magnetic vectors Q→1 and Q→2. Given an itinerant nature of magnetism in iron-pnictides, we develop a quasiclassical theory of tetragonal magnetic order in disordered three-band metal with anisotropic band structure. Within our model we find that the C4-symmetric magnetism competes with the C2-symmetric state with a single Q→ magnetic structure vector. Our main results is that disorder promotes tetragonal magnetic state which is in agreement with earlier theoretical studies.
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