Thermal entanglement in a two-qutrit system with nonlinear coupling under nonuniform external magnetic field

摘要

We study the thermal entanglement of a 2-qutrit spin chain with nonlinearcoupling in the presence of nonuniform magnetic field. Thermal entanglement ofan arbitrary (finite dimensional) m-partite system vanishes at some finitethreshold temperature T_s. We investigate the dependence of T_s on the system'sparameters, i.e. the nonlinear coupling and the magnetic field, for this2-qutrit system. In addition, we compare two lower bounds of I-concurrence forthis system and also study its dense coding capacity as a function of system'sparameters.