Quantum Steering And Decoherence In Low Dimensional Spin Systems

In the past few decades,quantum entanglement and Bell nonlocalization,which are symmetric quantum relationships,have attracted extensive attention and obtained fruitful research results.However,it is only in recent years that quantum steering,an asymmetric quantum relationship,has begun to come into view.It is a form of quantum correlation between quantum entanglement and Bell’s non-locality.Because of its unique asymmetric characteristics,it plays an irreplaceable role in many fields such as quantum communication,quantum computing and quantum cryptography.However,in the quantum field,an inevitable problem is that the quantum system will be coupled with the surrounding environment,leading to the rapid decay of quantum non-local correlation,the so-called quantum decoherence behavior,which seriously hinders the application of quantum correlation.Therefore,based on the one-dimensional spin chain model,this paper mainly studies the asymmetric and decoherence behavior of quantum steering.Firstly,we study quantum steering based on one-dimensional XXZ spin chain model in non-uniform magnetic field,using entropy uncertainty as measurement method.The asymmetric characteristics of quantum steering are mainly studied.The results show that the applied magnetic field,temperature and coupling parameters can significantly change the quantum steering and its asymmetry,and the increase of the applied magnetic field or temperature can inhibit the quantum steering.In particular,quantum steering disappears when temperature or magnetic fields exceed critical points.However,the asymmetry of quantum steering increases with increasing temperature or nonuniformity b of magnetic field.In addition,with the increase of anisotropic coupling parameter J_Z,the quantum steering is enhanced,while the asymmetry is weakened.Secondly,the intrinsic decoherence of quantum steering under one-dimensional XY spin chain model and the environment induced decoherence of quantum steering under one-dimensional XYZ spin chain model are studied respectively.The effects of magnetic field and anisotropy parameters on the robustness of quantum steering under different initial states are discussed.It is found that the intrinsic decoherence does not excite the asymmetric of the quantum steering,but the environmental induced decoherence behaves asymmetrically in a specific initial state.Moreover,quantum decoherence can be accelerated or slowed down by adjusting parameters and changing the initial state.