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

TL;DR

This paper investigates how nonlinear coupling and nonuniform magnetic fields affect thermal entanglement, threshold temperature, and dense coding capacity in a two-qutrit spin system, revealing parameter-dependent entanglement behavior.

Contribution

It provides a detailed analysis of thermal entanglement thresholds and compares bounds of I-concurrence in a 2-qutrit system with nonlinear interactions.

Findings

Thermal entanglement vanishes above a certain temperature T_s.

Dependence of T_s on nonlinear coupling and magnetic field parameters.

Comparison of two lower bounds of I-concurrence and their implications.

Abstract

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