Spin stiffness, spectral weight, and Landau damping of magnons in metallic spiral magnets

Abstract

We analyze the properties of magnons in metallic electron systems with spiral magnetic order. Our analysis is based on the random phase approximation for the susceptibilities of tight binding electrons with a local Hubbard interaction in two or three dimensions. We identify three magnon branches from poles in the susceptibilities, one associated with in-plane, the other two associated with out-of-plane fluctuations of the spiral order parameter. We derive general expressions for the spin stiffnesses and the spectral weights of the magnon modes, from which also the magnon velocities can be obtained. Moreover, we determine the size of the decay rates of the magnons due to Landau damping. While the decay rate of the in-plane mode is of the order of its excitation energy, the decay rate of the out-of-plane mode is smaller so that these modes are asymptotically stable excitations even in the presence of Landau damping.

arXiv comment31 pages, 7 figures

References in corpus (10)

• Crossover and scaling in a nearly antiferromagnetic Fermi liquid in two dimensions
• Incommensurate magnetic order and phase separation in the two-dimensional Hubbard model with nearest and next-nearest neighbor hopping
• Emergent topological spin structures in a centrosymmetric cubic perovskite
• Magnetic Phases of the 2D Hubbard Model at Low Doping
• Coexistence of incommensurate magnetism and superconductivity in the two-dimensional Hubbard model
• Fermi surface reconstruction and drop of Hall number due to spiral antiferromagnetism in high-$T_c$ cuprates
• Superconducting Spiral Phase in the two-dimensional t-J model
• Stability of the spiral phase in the 2D extended t-J model
• Longitudinal conductivity and Hall coefficient in two-dimensional metals with spiral magnetic order
• Charge carrier drop at the onset of pseudogap behavior in the two-dimensional Hubbard model