Optimal correlations in many-body quantum systems
Abstract
Information and correlations in a quantum system are closely related through the process of measurement. We explore such relation in a many-body quantum setting, effectively bridging between quantum metrology and condensed matter physics. To this aim we adopt the information-theory view of correlations, and study the amount of correlations after certain classes of Positive-Operator-Valued Measurements are locally performed. As many-body system we consider a one-dimensional array of interacting two-level systems (a spin chain) at zero temperature, where quantum effects are most pronounced. We demonstrate how the optimal strategy to extract the correlations depends on the quantum phase through a subtle interplay between local interactions and coherence.
Cite
@article{arxiv.1112.3280,
title = {Optimal correlations in many-body quantum systems},
author = {Luigi Amico and Davide Rossini and Alioscia Hamma and Vladimir E. Korepin},
journal= {arXiv preprint arXiv:1112.3280},
year = {2012}
}
Comments
5 pages, 5 figures + supplementary material. To be published in PRL