Thermal Entanglement In Heisenberg Model

As a result of Heisenberg spinning model suitable in many fields, the thermal entanglement based on this model attracts the widespread attention. The Heisenberg spinning model research has obtained the big development. The thermal entanglement in Heisenberg spinning model has the extremely hopeful application prospect.The dissertation first introduces the background knowledge of the quantum entanglement and summarizes the main results about two-qubit Heisenberg spinning model in domestic and foreign literature research. Thermal entanglement in the three-qubit XXZ model with non-nearest neighbor interaction and inhomogeneous magnetic field is studied.The result indicates that the nearest neighbor couplings may greatly enhance the entanglement between the nearest neighbor sites while the non nearest neighbor couplings have little or negative effects. For the non-nearest neighbor qubits, an opposite conclusion is seen. A large magnetic field at the middle qubit can induce a large non nearest neighbor entanglement. One more interesting phenomenon is that the nearest neighbor z-component coupling can shift the peaks of the non nearest neighbor entanglement.