Semiclassical dynamics of spin density waves

Abstract

We present a theoretical framework for equilibrium and nonequilibrium dynamical simulation of quantum states with spin-density-wave (SDW) order. Within a semiclassical adiabatic approximation that retains electron degrees of freedom, we demonstrate that the SDW order parameter obeys a generalized Landau-Lifshitz equation. With the aid of an enhanced kernel polynomial method, our linear-scaling quantum Landau-Lifshitz dynamics (QLLD) method enables dynamical SDW simulations with $N\simeq 10^5$ lattice sites. Our real-space formulation can be used to compute dynamical responses, such as dynamical structure factor, of complex and even inhomogeneous SDW configurations at zero or finite temperatures. Applying the QLLD to study the relaxation of a noncoplanar topological SDW under the excitation of a short pulse, we further demonstrate the crucial role of spatial correlations and fluctuations in the SDW dynamics.

17 pages, 5 figures

References in corpus (20)

• Spontaneous Skyrmion Ground States in Magnetic Metals
• Real time evolution using the density matrix renormalization group
• Theory of Intertwined Orders in High Temperature Superconductors
• The Kernel Polynomial Method
• Scalar spin chirality and quantum Hall effect on a triangular lattice
• Cluster Dynamical Mean Field Theory of the Mott Transition
• Spontaneous Magnon Decays
• Synchronization in the BCS Pairing Dynamics as a Critical Phenomenon
• The Hubbard model on the triangular lattice: Spiral order and spin liquid
• Nonthermal antiferromagnetic order and nonequilibrium criticality in the Hubbard model
• Formation of a topological non-Fermi liquid in MnSi
• Real-space calculation of the conductivity tensor for disordered topological matter
• Mott transition of fermionic atoms in a three-dimensional optical trap
• Magnon Decay in Noncollinear Quantum Antiferromagnets
• Flat spin wave dispersion in a triangular antiferromagnet
• Competition between Anderson localization and antiferromagnetism in correlated lattice fermion systems with disorder
• Spin Density Waves in the Hubbard model - A DMFT approach
• Testing the Monte Carlo - Mean Field approximation in the one-band Hubbard model
• Spontaneous quantum Hall effect via thermally induced quadratic Fermi point
• Incommensurate spiral magnetic order on anisotropic triangular lattice: Dynamical mean field study in a spin-rotating frame