Entanglement in quantum critical spin systems
摘要
We study the field dependence of the entanglement of formation in anisotropic S=1/2 antiferromagnetic chains and two-leg ladders displaying a T=0 field-driven quantum phase transition. The analysis is carried out via Quantum Monte Carlo simulations. At zero temperature the entanglement estimators show abrupt changes at and around criticality, vanishing below the critical field, in correspondence with an exactly factorized state, and then immediately recovering a finite value upon passing through the quantum phase transition. At the quantum critical point, a deep minimum in the pairwise-to-global entanglement ratio shows that multi-spin entanglement is strongly enhanced; moreover this signature represents a novel way of detecting the quantum phase transition of the system, relying entirely on entanglement estimators.
引用
@article{arxiv.quant-ph/0412056,
title = {Entanglement in quantum critical spin systems},
author = {Tommaso Roscilde and Paola Verrucchi and Andrea Fubini and Stephan Haas and Valerio Tognetti},
journal= {arXiv preprint arXiv:quant-ph/0412056},
year = {2007}
}
备注
5 pages, 4 figures. Contributed paper to the MQC2 conference, Naples 2004