2019/09/30 by Viktor Eisler, Florian Maislinger
Physics and Astronomy · #Classical XY model #Entropy (arrow of time) #Excitation #Ferromagnetism #Ground state #Magnetization #Physics of Superconductivity and Magnetism #Quantum entanglement #Quantum many-body systems #Quantum nonlocality #Topological Materials and Phenomena #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.21468/scipostphys.8.3.037
published as SciPost Phys. 8, 037 (2020) · 28 pages, 8 figures, minor changes
openalex created_date 2019/09/12 · arxiv created 2020/02/18 · openalex publication_date 2020/03/06 · arxiv updated 2020/03/09 · openalex updated_date 2026/08/06
We study the time evolution of magnetization and entanglement for initial states with local excitations, created upon the ferromagnetic ground state of the XY chain. For excitations corresponding to a single or two well separated domain walls, the magnetization profile has a simple hydrodynamic limit, which has a standard interpretation in terms of quasiparticles. In contrast, for a spin-flip we obtain an interference term, which has to do with the nonlocality of the excitation in the fermionic basis. Surprisingly, for the single domain wall the hydrodynamic limit of the entropy and magnetization profiles are found to be directly related. Furthermore, the entropy profile is additive for the double domain wall, whereas in case of the spin-flip excitation one has a nontrivial behaviour.