Control Of Asymmetric Quantum Steering For The Dissipation Quantum System

As a new research field,quantum information shows a very broad prospect of scientif-ic and technological application.As the key resource of quantum information,quantum correlation effects have been widely concerned and deeply studied by researchers,not only because they reflect the basic problems of quantum mechanics,but also have important applications in quantum computing and quantum information processing.The complex quantum correlation systems have different properties include entanglement,Bell inequali-ty,and quantum steering,which is a manifestation of quantum correlations intermediating between entanglement and Bell nonlocality.Quantum steering is intrinsically asymmet-ric,where it could be regarded as the distribution of entanglement from an untrusted party.It depends on the observers Alice and Bob and their roles are not interchange-able,which means that Bob,for example,can steer the state of Alice's particle but not vice versa,although the two particles are entangled with each other.This asymmetry is known as one-way steering.On the other hand,the quantum system is unavoidably coupled to the surrounding environment and exchange energy or information with it,and this phenomenon is called decoherence,in general,which is regarded as a serious enemy to quant.um mechanical syst,ems due to its negative influences on the atomic coherence and quantum correlations.Therefore,how to avoid the influence of environmental noise and even use environmental noise to prepare or enhance the quantum correlation has become an exciting research.Fortunately,dissipation can have a positive effect on the establishment of nonlocal quantum associations.In particular,the interaction between light and matter is used to establish the quantized Bogoliubov transform mode,and then the quantum reservoir theory makes the transformation mode of Bogoliubov evolve into a state where the number of photons is close to zero,which leads to the correlation between the original quantized modes.The paper proposes several feasible schemes for the prepa-ration of quantum steering under the noise environment,and its innovative work mainly includes the following aspects:Firstly,we obtain the steady state unidirectional EPR steering between two field modes by using the single-channel quantum dissipation process induced by atomic coherence.In this scheme,a double-cascade four-level atomic system is considered.Based on the full resonance interaction,all fields resonate with different atomic transitions,and the cavity fields generated by the mixing process induced by atomic coherence presents the EPR steering correlation.In terms of the method of the dressed-state representation and the Bogoliubov modes,the asymmetric couplings occur between the transformed modes and the dressed atoms,in which only one of the Bogoliubov modes is involved into the interaction with the dressed atoms and the other is excluded to the atomic reservoir.It is such an asymmetric interaction induces the asymmetric dissipation channel,through which one transformed mode undergoes annihilation due to absorption of the dressed atoms and the other still is not affected by the atoms.The results show that the one-way steering occurs from the Bogoliubov mode with more photons to the transformed mode with few photons,which is easily achieved via changing the intensity of an external field.There are some striking features in the present scheme.(?)The one-way steering is established under the condition of full resonance,where the resonant interactions appear not only between the electromagnetical fields and the bare atoms,but also between the Bogoliubov modes and dressed atoms.Furthermore,it is easy to achieve the asymmetric steering only via modulating the intensity of one of driving fields.(?)The asymmetric correlation occurs the field modes with large frequency difference.The cavity modes are generated from the different transitions and so they strongly depend on the atomic transition frequencies.With a proper choice of the coupled atoms,the steering could occur between the optical and microwave fields.(?)The present scheme is based on the dissipation of the atomic reservoir,which is robust against the stochastic fluctuations and is independent of the initial states for the field modes and atoms.Secondly,we explore the positive role of thermal noise on inducing the one-way EPR steering for a two-photon correlated emission laser(CEL)system in which the atomic coherence is initially prepared and the cavity is coupled to a thermal reservoir.In terms of the linear and adiabatic approximation in the good cavity limit,the steady-state quantum correlations of cavity modes could be obtained.For two cases of balanced and unbalanced cavity losses,the cavity mode from the upper transition can unidirectionally steer to the mode from the lower transition via the Gaussian measurement with the help of the thermal noise entering the cavity,which not only could induce the asymmetric steering but also expands the parameter region of the existing one-way steering at the steady state.Physically,the thermal noise highly increases the mean number of photon pairs of the superimposed radiation and significantly enlarges the intensity difference of the cavity modes,which induces the asymmetric mean photon numbers with larger difference and is more useful for implementing the one-way steering of the correlated laser.Finally,We show that decoherence could play positive role in generating one-way Einstein-Podolsky-Rosen(EPR)steering of two cavity fields dispersively interacting with a single four-level atom,each of which is independently coupled to a thermal reservoir.In the low-Q and weak Raman transition regimes,two output fields exhibit the asymmetric EPR steering and the steering direction could be easily controlled via adjusting the mean photon numbers of the thermal reservoirs and the decay rates of cavities.The striking features are included in the present scheme.First,the one-way EPR steering is achieved via using the couplings of the cavities with the heat baths,which sheds light on the quantum state manipulation in the presence of decoherence.Second,the obtainable EPR steering occurs between the cavity fields in the low-Q regime,which relaxes the constraint on the use of good cavities and so makes our scheme more practical.Third,the correlation properties of the output modes are under our consideration,which can be measured more conveniently.