摘要
We propose two schemes for realizing quantum secure direct communication (QSDC)by using a set ofordered two-photon three-dimensional hyperentangled states entangled in two degrees of freedom (DOFs)as quantuminformation channels.In the first scheme,the photons from Bob to Alice are transmitted only once.After insuring thesecurity of the quantum channels,Bob encodes the secret message on his photons.Then Alice performs single-photontwo-DOF Bell bases measurements on her photons.This scheme has better security than former QSDC protocols.In thesecond scheme,Bob transmits photons to Alice twice.After insuring the security of the quantum channels,Bob encodesthe secret message on his photons.Then Alice performs two-photon Bell bases measurements on each DOF.The schemehas more information capacity than former QSDC protocols.
基金
Supported by the National Natural Science Foundations of China under Grant Nos. 10904066 and 11004096
the State Key Program for Basic Research of China under Grant No. 2011CBA00205
作者简介
Corresponding author, E-maih pingxu520@nju.edu.cnE-mail： ybzhan@hytc.edu.cn
