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Résumé |
We study the dynamics of a quantum spin chain (S=1/2 XXZ model), which is prepared at t=0 in a domain-wall initial sate, where the spins are initially
pointing up on the left half-line and down on the right half-line.
Using extensive time-dependent DMRG simulations we analyze the evolution of the magnetization profile, as a function of the anisotropy parameter (Delta) the Hamiltonian.
These numerical results are compared with the predictions of a recently developed hydrodynamics approach [Castro-Alvaredo et al., PRX 2016 and Bertini et al. PRL 2016], which generalizes the conventional hydrodynamics to integrable one-dimensional quantum systems. For this domain wall problem the situation of the isotropic Heisenberg model (Delta=1) is particularly interesting and not yet fully understood,
and at this point our data suggest a diffusive behavior [Misguich, Mallick & Krapivksy, PRB 2017]. |
