Quantum Entanglement And Quantum Steering Based On Dissipative Mechanism

For a long time,quantum correlation,including quantum entanglement and quantum steering,has been a basic and important topic research in quantum mechanics and quantum information science.As the core resource of quantum information,stable and sustainable quantum correlation with easy preparation,high compression and entanglement,good application prospects has always been an important goal of research.It is found that the process of preparing and using quantum entanglement will be affected by the environment,resulting in the dissipation process,which leads to the disappearance of quantum entanglement on the one hand.On the other hand,under certain conditions,the pure dissipation process leads to the enhancement of entanglement,so it can be used as a means to prepare quantum entanglement and gradually become one of the research hotspots.The result shows that the nonlinear effect in the atomic system contains a dissipation process,which leads to compression and entanglement.Because of its relatively simple manipulation,the quantum correlation effect of continuum variables has received more extensive attention and in-depth research.The typical mechanism for preparing continuum variable entanglement is the nonlinear process of parametric interaction.According to these theories,in different systems,correlated radiation laser,quantum beat,two-photon process and dark state resonance induced by atomic coherence effect are proposed to prepare quantum entanglement or quantum steering respectively.Among these mechanisms,atomic reservoir mechanism is proposed as a typical scheme to prepare photon entanglement,optomechanical entanglement and entanglement between mixed objects.We note that the two-level atomic system is proposed to prepare stable quantum entanglement,and its internal physical process is based on the dissipation process of single channel.Our further research extends it to three-level system.It is found that the dissipation process of two channels can be established and lead to perfect quantum entanglement.The advantage of these schemes is that they do not need to prepare non classical states initially,and are suitable for resonant and non resonant atomic systems.However,can we produce stable quantum entanglement without increasing the number of atoms or in condition of weak coupling?Can this dissipative and nonlinear interaction mechanism produce more stringent quantum steering?Is this mechanism applicable to other systems?In this paper,I take superconducting artificial atoms and monatomic systems as examples to prepare stable quantum entanglement and steering effects by using dissipative reservoir theory.It provides an effective reference for the regulation of quantum communication and quantum information processing.The main research contents are as follows:Firstly,preparation of stable quantum entanglement between two cavity modes using phase dependent dissipative mechanism.In a superconducting artificial atom system,I use three microwave fields to interact with three-level Δ-type atoms at the same time to form a closed ring structure,and two quantum cavity modes are coupled with two transitions respectively.According to the dressed state theory and Bogoliubov mode transformation,I find that the collective phase between the three strong driving fields can be used to effectively control the atomic reservoir effect.When Φ=0,the system likes a two-level atomic reservoir,forming a single dissipative channel.Based on this channel,stable quantum entanglement can be generated.When Φ=π/2 or 3π/2,the system likes a three-level atomic reservoir,forming a double dissipative channel.At this time,stronger steady-state quantum entanglement can be obtained.Our results show that the dissipative reservoir effect can be effectively controlled by adjusting the relative phase.Secondly,preparation of stable entanglement and steering between two cavity modes by using the dissipative mechanism in monatomic system.Previous studies have shown that under the condition of large detuning,single atom system can be used to prepare quantum entanglement under the condition of weak coupling,but the entanglement usually disappears with the evolution of time.Based on a typical four state monatomic system,I use two strong fields to couple two dipole transitions respectively,and two quantum fields to couple with the other two dipole transitions.Under the condition of symmetry,according to the dissipative reservoir theory,I prove that the single atom system behaves as a two-level atomic reservoir.When the two quantum fields are resonantly coupled with the blue and red sidebands in the decorated state picture,stable quantum entanglement can be obtained.Furthermore,I find that the quantum entanglement will increase to a stable value with the increase of coupling strength.When the coupling strength of two quantum modes is not equal,quantum steering can be obtained in the region with large entanglement value.Our results show that a monatomic system does not need large detuning conditions and can use the atomic reservoir mechanism to prepare stable quantum correlations,which is completely different from the previous work not only in terms of conditions but also in terms of internal mechanism.Finally,preparation of stable quantum steering between two cavity modes using resonance driven dissipative mechanism.Previous work shows that in the superconducting three-level Δ-type system,I use the relative phase controlled resevoir effect to prepare stable quantum entanglement.Inspired by this,I consider a superconducting artificial atom system driven by two resonant fields.I do not need to adjust the relative phase.By adjusting the relative intensity between the two fields,I can obtain stable one-way and two-way quantum steering.Furthermore,I discuss and analyze the relationship between the correlation effect and quantum entanglement,one-way quantum steering and two-way quantum steering.It is found that although the properties of two-way quantum steering are similar to entanglement,the conditions are more strict.I also discuss the stable region of steering according to the actual experimental parameters,which lays a foundation for the experimental realization of quantum steering in superconducting circuits.