Quantum Correlation Transfer By Optomechanical Effects

In quantum communication neighborhood formed by the combination of tradi-tional communication science and quantum mechanics, the photon as a carrier of quantum information plays an important role, but quantum information can not be stored easily because of decoherence caused by environmental effects. Based on this, a growing number of studied tend to transfer the information carried by the light field to other material, for example, people had tried to make atom carry the quan-tum information field glazing by irradiating atom with light field, atomic memory effect is the outcome in this regard. However, studies have shown that atoms can not completely absorb the quantum information in light field. In recent years, it was discovered that the entanglement of light can be transferred on macroscopic mate-rial, the experiment has been achieved entangling a pair of movable mirrors with a pair of EPR entangled input fields by optomechanical system. In the entanglement swapping process, two related objects do not meet directly, optomechanical system as the third part to exchange both properties. Such transfer mode makes the quantum information avoid weakening too fast for noise in long distance transmission.The mode that transferring the entanglement of light in the macroscopic objects has been widely used in the quantum information. Currently,"one to one" mode of transmission, that is two harmonic oscillators are driven by two-mode squeezed input field separated. However, in reality, this mode over a single pass and can not meet the need. In this paper, we show two different transfer modes, respectively,"two to one" and "one to two" transmission mode. In "two to one" transfer mode, taking a separated two-mode squeezed field as noise sideband of input field, and the two modes drive the cavitied from opposite direction. The result shows that the squeezing of two-mode squeezed light can be transferred on a single movable mirror perfectly. In "one to two" transfer mode, two parts are showed. One is that the squeezing of one single squeezed field is transferred on two movable mirrors by optomechanical sys- tem. The other is that two single mode squeezed fields are superimposed at a lossless beam-splitter, and are separated into two beams, which are used to drive to separated cavities. In the calculation of quantum fluctuation, two cases are discussed. For one one of the two single mode field is as vacuum field, the result show the two movable mirrors can be entangled. For the second, the noise sideband are two single mode squeezed fields and the intensity of squeezing for two input fields is always same, the result shows the two movable mirrors can be at EPR entangled states. For the last, the intensity of one in two input fields is fixed, from the result, the entanglement of two movable mirrors is obtained, but the intensity of entanglement is not high.