English

Entanglement in XY Spin Chain

Quantum Physics 2009-11-10 v4 Statistical Mechanics Exactly Solvable and Integrable Systems

Abstract

We consider the ground state of the XY model on an infinite chain at zero temperature. Following Bennett, Bernstein, Popescu, and Schumacher we use entropy of a sub-system as a measure of entanglement. Vidal, Latorre, Rico and Kitaev conjectured that von Neumann entropy of a large block of neighboring spins approaches a constant as the size of the block increases. We evaluated this limiting entropy as a function of anisotropy and transverse magnetic field. We used the methods based on integrable Fredholm operators and Riemann-Hilbert problem. The entropy is singular at phase transitions.

Keywords

Cite

@article{arxiv.quant-ph/0409027,
  title  = {Entanglement in XY Spin Chain},
  author = {A. R. Its and B. -Q. Jin and V. E. Korepin},
  journal= {arXiv preprint arXiv:quant-ph/0409027},
  year   = {2009}
}

Comments

8 pages and 2 figures