Semiclassical dynamics of spin density waves

ORAL

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.

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Presenters

  • Gia-Wei Chern

    Department of Physics, University of Virginia, University of Virginia, Physics, University of Virginia, Department of Physics, Univ of Virginia

Authors

  • Gia-Wei Chern

    Department of Physics, University of Virginia, University of Virginia, Physics, University of Virginia, Department of Physics, Univ of Virginia

  • Kipton Barros

    Theoretical Division, Los Alamos National Laboratory, Los Alamos National Lab, Los Alamos National Laboratory

  • Zhentao Wang

    Physics, University of Tennessee, The University of Tennessee, Univ of Tennessee, Knoxville

  • Hidemaro Suwa

    Physics, University of Tennessee

  • Cristian Batista

    Department of Physics and Astronomy, Univ of Tennessee, Knoxville, Univ of Tennessee, Knoxville, Department of Physics and Astronomy, The University of Tennessee, University of Tennessee, Physics, University of Tennessee, The University of Tennessee, Department of Phys., Univ. of Tennessee, U. Tennessee, Knoxville, University of Tennessee, Knoxville