In the present article, we explore a suitable coarse-graining channel as a tool to describe effective entanglement spreading in a coarse-grained spin chain with different degrees of resolution. Comparing it with the experimental realizations performed with ultracold atoms, our results suggest that even if we are not able to fully resolve the system, entanglement can still be detected for some coarse-graining levels. Furthermore, we show that it is possible to have some information about the “microscopic” entanglement, even if we only have access to the system's coarse-grained description. We show that the amount of entanglement decays exponentially with the lack of system resolution. The lack of experimental resolution might thus lead to an effective classical description.

• Received 1 April 2019

DOI:https://doi.org/10.1103/PhysRevA.100.022334