Criticality, factorization, and long-range correlations in the anisotropic XY model

Steve Campbell*, Jonathan Richens, Nicola Lo Gullo, Thomas Busch

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)

Abstract

We study the long-range quantum correlations in the anisotropic XY model. By first examining the thermodynamic limit, we show that employing the quantum discord as a figure of merit allows one to capture the main features of the model at zero temperature. Furthermore, by considering suitably large site separations we find that these correlations obey a simple scaling behavior for finite temperatures, allowing for efficient estimation of the critical point. We also address ground-state factorization of this model by explicitly considering finite-size systems, showing its relation to the energy spectrum and explaining the persistence of the phenomenon at finite temperatures. Finally, we compute the fidelity between finite and infinite systems in order to show that remarkably small system sizes can closely approximate the thermodynamic limit.

Original languageEnglish
Pages (from-to)062305-1 to 062305-8
Number of pages8
JournalPhysical Review A (Atomic, Molecular, and Optical Physics)
Volume88
Issue number6
DOIs
Publication statusPublished - 03 Dec 2013
Externally publishedYes

Keywords

  • STATISTICAL-MECHANICS
  • BROKEN SYMMETRY
  • CRITICAL-POINT
  • QUANTUM
  • ENTANGLEMENT
  • STATE

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