Recently, Xiu et al. [Commun. Theor. Phys. 49 （2008） 905] proposed two schemes of teleporting an N particle arbitrary and unknown state when N groups of three particle general W states are utilized a.s quantum chann...Recently, Xiu et al. [Commun. Theor. Phys. 49 （2008） 905] proposed two schemes of teleporting an N particle arbitrary and unknown state when N groups of three particle general W states are utilized a.s quantum channels. They gave the maximal probability of successful teleportation. Here we find that their operation is not the optimal and the successful probability of the teleportation is not maximum. Moreover, we give the optimal schemes operation and obtain maximal successful probability for teleportation.展开更多
The probabilistic quantum teleportation scheme [Phys. Lett. A 305 （2002） 12] is improved via two seemingly different methods （i.e., the usual aneilla method and the so-called Kraus method）, respectively. The essen...The probabilistic quantum teleportation scheme [Phys. Lett. A 305 （2002） 12] is improved via two seemingly different methods （i.e., the usual aneilla method and the so-called Kraus method）, respectively. The essence of the improvements is to fetch a part from the residues so that the success probability is accordingly increased. The two improved versions and a similar protocol proposed by Li et al. [Phys. Rev. A 61 （2000） 034301] are compared mutually and discussed. It is found that they are equally efficient and can reach the success probability threshold determined by the inherent entanglement of the quantum channel.展开更多
We investigate the effect of phase shift on the perfect state transfer through two parallel one-dimensional ring-shaped spin chains. We find that the total success probability can be significantly enhanced by phase sh...We investigate the effect of phase shift on the perfect state transfer through two parallel one-dimensional ring-shaped spin chains. We find that the total success probability can be significantly enhanced by phase shift control when the communication channel consists of two odd chains. The average time to gain unit success probability is discussed, showing that a proper phase shift can be used to enhance the efficiency of state transmission.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 10902083the Natural Science Foundation of Shannxi Province under Grant No. 2009GM1007
文摘Recently, Xiu et al. [Commun. Theor. Phys. 49 （2008） 905] proposed two schemes of teleporting an N particle arbitrary and unknown state when N groups of three particle general W states are utilized a.s quantum channels. They gave the maximal probability of successful teleportation. Here we find that their operation is not the optimal and the successful probability of the teleportation is not maximum. Moreover, we give the optimal schemes operation and obtain maximal successful probability for teleportation.
基金Supported by the Program for New Century Excellent Talents at the University of China under Grant No.NCET-06-0554the National Natural Science Foundation of China under Grant Nos.10975001,60677001,10747146,and 10874122+3 种基金the Science-Technology Fund of Anhui Province for Outstanding Youth under Grant No.06042087the General Fund of the Educational Committee of Anhui Province under Grant No.2006KJ260Bthe Natural Science Foundation of Guangdong Province under Grant Nos.06300345 and 7007806 the Talent Foundation of High Education of Anhui Province for Outstanding Youth under Grant No.2009SQRZ018
文摘The probabilistic quantum teleportation scheme [Phys. Lett. A 305 （2002） 12] is improved via two seemingly different methods （i.e., the usual aneilla method and the so-called Kraus method）, respectively. The essence of the improvements is to fetch a part from the residues so that the success probability is accordingly increased. The two improved versions and a similar protocol proposed by Li et al. [Phys. Rev. A 61 （2000） 034301] are compared mutually and discussed. It is found that they are equally efficient and can reach the success probability threshold determined by the inherent entanglement of the quantum channel.
基金Supported by National Natural Science Foundation of China under Grant Nos.11005099,60677044the Fundamental Research Funds for the Central Universities under Grant No.201013037
文摘We investigate the effect of phase shift on the perfect state transfer through two parallel one-dimensional ring-shaped spin chains. We find that the total success probability can be significantly enhanced by phase shift control when the communication channel consists of two odd chains. The average time to gain unit success probability is discussed, showing that a proper phase shift can be used to enhance the efficiency of state transmission.
