The study of the entanglement evolution after a global quantum quench has become in the last two decades a prominent research area, at the intersection between theoretical condensed matter, quantum information and experimental cold-atoms and ion-traps physics. More recently, the resolution of entanglement in the various symmetry sectors of a quantum many-body system with a global conserved charge gained a lot of interest within the entanglement community. In particular, some experimental papers argued that a better understanding of this symmetry resolved entanglement is necessary for a better understanding of the non-equilibrium dynamics of quantum many-body systems. In this talk I am going to show some recent results of my work done in collaboration with Gilles Parez from University of Louvain under the supervision of Prof. Pasquale Calabrese, in which we initiate the study of the evolution of the symmetry resolved entanglement after a global quantum quench in quantum many-body systems. In the context of free fermions and conformal field theories, we are able to provide analytical results for the relevant time-dependent quantities, and shed light on two new physical phenomena. First, the symmetry resolved Renyi entropies start evolving with a calculable time delay that depends on the charge sector. Second, there is an effective equipartition of the entanglement in the limit of large subsystem size. We argue that these phenomena occur in more general quantum systems, as they can be understood from the quasiparticle picture for the spreading of entanglement.
Reference: https://arxiv.org/abs/2010.09794