If the information is encoded into the state of the subsystem $S$ of a quantum system initially (at $t=0$), then it becomes distributed over the whole quantum system at $t>0$ due to the quantum interactions. Consequently, this information, in general, can be extracted, either completely or partially, from any subsystem of a quantum system. { We suggest a method of extraction of information, which is based on the polarization measurements on the receiver $R$}.
Categories: quant-ph
