Information propagation in a quantum system. Examples of open spin-1/2 chains

TL;DR

This paper discusses how information initially localized in a subsystem of a quantum spin chain disperses throughout the system over time and proposes a measurement-based method to extract this information from any part of the system.

Contribution

It introduces a new measurement method based on polarization measurements for extracting information from quantum spin chains.

Findings

Information disperses over the entire quantum system over time.

The proposed measurement method allows partial or complete information retrieval.

The approach is applicable to open spin-1/2 chains.

Abstract

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 $R$}.