Qin, Meng; Ge, Xing; Zhai, Xiao-Yue; Liu, Cui-Cui; Wang, Bi-Li Effects of nonlinear couplings on entanglement in a two-qutrit Heisenberg \(XXX\) chain under an inhomogeneous magnetic field. (English) Zbl 1264.82085 Commun. Theor. Phys. 55, No. 3, 431-433 (2011). Summary: This paper investigates the entanglement of a two-qutrit Heisenberg \(XXX\) chain with nonlinear couplings under an inhomogeneous magnetic field. By the concept of negativity, we find that the critical temperature increases with the increase of inhomogeneous magnetic field \(b\). Our study indicates that for any \(| K| >| J|\), or \(| K| <| J|\) entanglement always exists for certain regions. We also find that at the critical point, the entanglement becomes a nonanalytic function of \(B\) and a quantum phase transition occurs. MSC: 82C20 Dynamic lattice systems (kinetic Ising, etc.) and systems on graphs in time-dependent statistical mechanics 81P40 Quantum coherence, entanglement, quantum correlations 82C27 Dynamic critical phenomena in statistical mechanics 82C26 Dynamic and nonequilibrium phase transitions (general) in statistical mechanics 78A60 Lasers, masers, optical bistability, nonlinear optics Keywords:entanglement; negativity; nonlinear couplings; inhomogeneous magnetic field PDFBibTeX XMLCite \textit{M. Qin} et al., Commun. Theor. Phys. 55, No. 3, 431--433 (2011; Zbl 1264.82085) Full Text: DOI