Abstract： It is shown that only the maximally entangled two-particle (spin 1/2) states whose one-particle reduced density matrix is ρ(i) = (1/2)I2 can realize the teleportation of an arbitrary one-particle spin state. Based on this, to teleport an arbitrary k-particle spin state, one must prepare an N-particle entangled state whose k-particle (k < N) reduced density matrix has the structure 2-kI2k (I2k being the 2k x 2k identity matrix). The N-particle Greenberger-Horne-Zeilinger states cannot realize the teleportation of an arbitrary k-particle (N > k ≥ 2) state, except for special states with only two components.
ZHU Hong-Bo;ZENG Jin-Yan. Possibility of Quantum Teleportation and the Reduced Density Matrix
[J]. 中国物理快报, 2001, 18(7): 860-863.
ZHU Hong-Bo, ZENG Jin-Yan. Possibility of Quantum Teleportation and the Reduced Density Matrix
. Chin. Phys. Lett., 2001, 18(7): 860-863.
2001, Vol. 18 
