We consider quantum systems in entangled states postselected in nonentangled states. Such systems exhibit unusual behavior, in particular, when weak measurements are performed at intermediate times.
Aharonov, Yakir, Shmuel Nussinov, Sandu Popescu, and Lev Vaidman. "Peculiar Features of Entangled States with Postselection." Physical Review A 87.1 (2013). DOI: 10.1103/PhysRevA.87.014105
American Physical Society