Abstract Thermal entanglement, as influenced by interaction parameters, is investigated within the general Heisenberg XYZ model. We calculate the relationship between entanglement and the system interaction parameters, including spin–spin interaction parameters (SSIPs) and spin–orbit interaction parameters (SOIPs). By considering various parameter orientations, we identify four optimal combinations of the SSIPs and find that the optimal vector of the spin–orbit interaction aligns with the coordinate axis corresponding to the maximal SSIP component. Furthermore, we obtain three effective optimal combinations of the SOIPs corresponding to the optimal SSIPs, which can maximize the system entanglement when the parameters are tuned accordingly. To demonstrate the feasibility of our results under realistic experimental conditions, we propose an optical lattice scheme with tunable parameters.
In this paper, we study the thermal entanglement in a two-qubit Heisenberg XYZ system with different Dzyaloshinskii–Moriya (DM) couplings. We show that different DM coupling parameters have different influences on the entanglement and the critical temperature. In addition, we find that when Ji (i-component spin coupling interaction) is the largest spin coupling coefficient, Di (i-component DM interaction) is the most efficient DM control parameter, which can be obtained by adjusting the direction of DM interaction.
The effects of initial conditions and system parameters on entanglement dynamics and asymptotic entanglement for a two-qubit anisotropic XY Heisenberg system in the presence of an inhomogeneous magnetic field and spin-orbit interaction are investigated. We suppose that each qubit interacts with a separate thermal reservoir which is held in its own temperature. The effects of the parameters of the system and environment like spin-orbit interaction and temperature difference of reservoirs are also discussed.
The role of spin-orbit interaction in the ground state and thermal entanglement of a Heisenberg
XYZ two-qubit system in the presence of an inhomogeneous magnetic field is investigated. We show that the ground state entanglement tends to vanish suddenly for a certain value of the spin-orbit parameter
D and, when
D crosses its critical value
Dc, the entanglement undergoes a revival. Indeed, when
D crosses its critical value
(Dc), the ground state entanglement tends to its maximum value
(C=1). Also, at finite temperatures there are revival regions in the $D\text{\ensuremath{-}}T$ plane. In these regions, entanglement first increases with increasing temperature and then decreases and ultimately vanishes for temperatures above a critical value. We find that this critical temperature is an increasing function of
D and that the amount of entanglement in the revival region depends on the spin-orbit parameter. Therefore when spin-orbit interaction is included larger thermal entanglement can exist at higher temperatures. We also show that the rate of enhancement of thermal entanglement by
D is not the same for ferromagnetic
(Jz<0) and antiferromagnatic
(Jz>0) chains. The entanglement teleportation via the quantum channel constructed by the above system is also investigated, and the influence of the spin-orbit interaction on the fidelity of teleportation and entanglement of replica states is studied. We show that, by introducing spin-orbit interaction, the entanglement of the replica state and fidelity of teleportation can be increased for the case of
Jz<0. We also argue that a minimal entanglement of the channel is required to realize efficient entanglement teleportation and, in the case of
Jz<0, this minimal entanglement can be achieved by introducing spin-orbit interaction.
The effects of spin-spin interaction on thermal entanglement of a two-qubit Heisenberg XYZ model with different inhomogeneous magnetic fields are investigated. It is shown that the entanglement is dependent on the spin-spin interaction and the inhomogeneous magnetic fields. The larger the J i (i-axis spin-spin interaction), the higher critical value the B i (i-axis uniform magnetic field) has. Moreover, in the weak-field regime, the larger J i corresponds to more entanglement, while in the strong-field regime, different J i correspond to the same entanglement. In addition, it is found that with the increase of J i , the concurrence can approach the maximum value more rapidly for the smaller B i , and can reach a larger value for the smaller b i (i-axis nonuniform magnetic field). So we can get more entanglement by increasing the spin-spin interaction J i , or by decreasing the uniform magnetic field B i and the nonuniform magnetic field b i .