Research On EPR Steering In The Controllable Thermal Dynamical Casimir Arrays At Finite Temperature

When boundary conditions are changed rapidly,photons are produced from the vacuum,an effect commonly known as the dynamic Casimir effect(DCE).Moore first predicted this effect in 1970 by studying a cavity made up of two moving,ideal mirrors.In 2011,Wilson et al.observed the dynamic Casimir effect in superconducting circuits at first time.Nonclassical photon pairs are often used as coherent light sources to study some quantum correlation problems,such as EPR steering.Considerer two remote observers,Alice and Bob,share a pair of entangled particles and an observer,if Alice can predict the state of Bob’s particles through different types of measurement of her own particles,this is EPR steering,and steering is Alice’s ability to control Bob through local measurements.Because of the asymmetry between the two observers,the EPR steering is a quantum correlation between quantum entanglement and Bell non-locality,and EPR steering has been experimentally implemented in many different systems.Quantum steering also plays an important role in quantum information such as quantum cryptography.Driven by the demand for large-scale entangled state construction in quantum networks,EPR steering also expands to multi-party steering.Monogamy is a basic feature of multi-party EPR steering.Taking the three-party system as an example,there are three parties,namely Alice,Bob and Charlie,and monogamy relation means that Alice and Bob cannot steer Charlie at the same time.By breaking the constraint of monogamy relation,more configurations of multi-party EPR steering can be displayed,which is called shareability of EPR steering.Many studies have shown that the constraints of monogamy relation can be removed by increasing the number of measurement Settings.Previous work in our group has studied EPR steering and sudden death by adjusting coupling strength and detuning,and exchange and swapping of monogamy relations by adjusting coupling strength and detuning for multiparty EPR steering.Since most of the current work about EPR steering in vacuum environment,the influence of temperature on EPR steering is not considered.In this paper,we study EPR steering at finite temperature by having temperature to existing superconducting quantum circuits.It was found that EPR steering could be controlled by temperature.The higher the temperature,the stronger the inhibition effect to accelerate the sudden death of EPR steering.Only the steered party have temperature,it can inhibit the EPR steering,it leads some characteristics of EPR steering can be realized by controlling the temperature.We also found it is more simply to realize shareability of EPR steering by having temperature to the steered superconducting quantum resonator and cooperating with the regulating coupling parameters or detuning.