Zero-magnon sound in quantum Heisenberg ferromagnets

Abstract

Using a functional renormalization group approach we show that at low temperatures and in a certain range of magnetic fields the longitudinal dynamic structure factor of quantum Heisenberg ferromagnets in dimensions $D\le 2$ exhibits a well-defined quasi-particle peak with linear dispersion that we identify as zero-magnon sound. In $D>2$ the larger phase space available for the decay into transverse spin waves leads only to a broad hump centered at zero frequency whose width scales linearly in momentum.

6 pages, 3 figures

References in corpus (2)

• From local to critical fluctuations in lattice models: a non-perturbative renormalization-group approach
• Spin functional renormalization group for quantum Heisenberg ferromagnets: Magnetization and magnon damping in two dimensions

Cited by in corpus (12)

• Pseudo-fermion functional renormalization group for spin models
• Dissipative spin dynamics in hot quantum paramagnets
• Breaking down the magnonic Wiedemann-Franz law in the hydrodynamic regime
• Critical spin dynamics of Heisenberg ferromagnets revisited
• Spin functional renormalization group for the $J_1{J}_2{J}_3$ quantum Heisenberg model
• Spectral representation of Matsubara n-point functions: Exact kernel functions and applications
• Phase diagram of the $J_1$-$J_2$ quantum Heisenberg model for arbitrary spin
• Recursive algorithm for generating high-temperature expansions for spin systems and the chiral non-linear susceptibility
• Functional renormalization group without functional integrals: implementing Hilbert space projections for strongly correlated electrons via Hubbard X-operators
• Functional renormalization group for extremely correlated electrons
• Keldysh pseudo-fermion functional renormalization group for quantum magnetism
• Spin functional renormalization group for dimerized quantum spin systems