Continuous Variable Minimum Associated With The Mixed State Of A Number Of Issues Research

Non-classical optical field has a very vital position in the quantum optics and quantum information because of its unique properties. Since non-classical optical field have obvious different feature from classical optical field, especially that the pressure optical field has smaller noise fluctuation on a component than others, using it as information carrier, we can obtain higher signal-to-noise and it will be an attractive information carrier.Quantum information science, which mainly includes quantum computer and quantum communication, has increasingly evolved as a new subject. Entanglement is one of the most striking features of quantum mechanics and it plays key pole in all fields of quantum information science, which encourages more and more people studying the properties of quantum entanglement states. At present, the study of two-body quantum system has been wide and incisive. The theory about pure state is wonderful, but the theory about mixed state is not incisive. As mixed states widely exist in practical quantum systems, the study of it will have an important applied value.In this paper we study the two-mode minimum correlation state, which was mentioned by Agarwal in 2003 based on the method that proposed by Ponomarenko in 2001. The main contents of this thesis are as follows:1. We study the quantum statistical properties of minimum correlation states in different coefficients. Our results show that the minimum correlation states disobey classical Cauchy-Schwartz inequality and exhibit the non-classical correlations. In addition, we study the non-classical properties about squeezing and sub-Poissonian statistics of minimum correlation states.2. We study the two-mode minimum-correlation mixed state (a kind ofgeneralized Einstein-Podolsky-Rosen type states)-the relation between theentanglement degrees and squeezing parameters is analyzed. We find that there exists the minimum value of squeezing parameter when the two-mode minimumcorrelation mixed state is entangled. In addition, the Wehrl's entropy and the total variance of minimum correlation state are also studied.3. We study the quantum teleportation employing two-mode squeezedvacuum state as quantum channel based on the scheme of Braunstein and Kimble. The results show that we can teleportate the single mode minimum correlation state with no squeezing in high fidelity but telepotate the state with squeezing in a low fidelity. Additionally, we find that it can't optimize the fidelity of single mode minimum correlation mixed state by tuning displacement factor.