Ultrafast dynamics of entanglement in Heisenberg antiferromagnets

Abstract

We investigate entanglement dynamics in the antiferromagnetic Heisenberg model in two dimensions following a spatially anisotropic quench of the exchange interactions. Opposed to established results in one dimension, the magnon quasiparticles show an initial growth of entanglement dynamics that does not depend on the system size and is governed by the oscillation period of the exchange interaction. We ascribe this to the dominance of the intrinsic entanglement of short wavelength nonpropagating magnon pairs, which also leads to a competition between area-law and volume-law contribution in the entanglement dynamics. Furthermore, by adopting the neural-network quantum states, we provide numerical evidence that this behavior survives even in the presence of strong magnon-magnon interactions, suggesting intriguing avenues for manipulating entanglement dynamics in quantum materials.

Selection rules for ultrafast laser excitation and detection of spin correlation dynamics in a cubic antiferromagnet

“…So far, different works were describing the spin dynamics triggered by laser-induced perturbation of * Fedianin.A.E@mail.ioffe.ru exchange using terminology originating from quantum information science, such as magnon squeezing [15,21], and magnon entanglement driving longitudinal oscillations of the antiferromagnetic vector [16,18,22]. However, as it was emphasized in several theoretical studies [11,13,14,18,23,24], such dynamics is closely related to correlations between spins at nearest-neighbor sites, which therefore is an another important parameter which needs to be analyzed for comprehensive understanding of the spin dynamics triggered by laser-induced exchange perturbation [11,18,22,23,25,26]. Indeed, the sign and magnitude of spin-spin correlations that characterize a particular magnetic state are unambiguously connected with the sign and strength of the exchange interaction.…”