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arXiv · 1112.3280

Optimal correlations in many-body quantum systems

Luigi Amico·Davide Rossini·Alioscia Hamma·Vladimir E. Korepin
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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.

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Luigi Amico, Davide Rossini, Alioscia Hamma, Vladimir E. Korepin. 2012-05-22. Optimal correlations in many-body quantum systems. https://doi.org/10.1103/physrevlett.108.240503

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