2003/05/31 by J. Vidal, Julien Vidal, Guillaume Palacios +3 · 9 citations
Computer Science · Mathematics · Physics and Astronomy · #Concurrence #Cusp (singularity) #Ground state #Lambda #Mathematics #Order (exchange) #Phase transition #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum critical point #Quantum entanglement #Quantum many-body systems #Quantum mechanics #Quantum phase transition #Singularity #Spin (aerodynamics) #cond-mat.str-el #quant-ph
paper · pdf · doi:10.1103/physreva.69.022107
published as Phys. Rev. A 69, 022107 (2004) · 4 pages, 4 EPS figures, minor corrections added and title changed
arxiv created 2003/12/02 · openalex publication_date 2004/02/18 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider a system of mutually interacting spins 1/2 embedded in a transverse magnetic field which undergoes a second-order quantum phase transition. We analyze the entanglement properties and the spin squeezing of the ground state and show that, contrarily to the one-dimensional case, a cusplike singularity appears at the critical point \ensuremathλc in the thermodynamical limit. We also show that there exists a value \ensuremathλ0>~\ensuremathλc above which the ground state is not spin squeezed despite a nonvanishing concurrence.