We investigate quantum phase transitions in various spin chain systems using the multipartite entanglement measure τSEF based on the monogamy inequality of squared entanglement of formation. Our results demonstrate that τSEF is more effective and reliable than bipartite entanglement or bipartite correlation measures such as entanglement of formation, von Neumann entropy, and quantum discord in characterizing quantum phase transitions. τSEF not only detects critical points that may go unnoticed by other detectors but also avoids the issue of singularity at non-critical points encountered by other measures. Furthermore, by applying τSEF, we have obtained the phase diagram for the XY spin chain with three and four interactions and discovered a new quantum phase.
@article{arxiv.2401.15593,
title = {Multipartite entanglement serves as a faithful detector for quantum phase transitions},
author = {Y. C. Li and Y. H. Zhou and Y. Zhang and Y. K. Bai and H. Q. Lin},
journal= {arXiv preprint arXiv:2401.15593},
year = {2024}
}