Comment on “General relation between the transformation operator and an invariant under stochastic local operations and classical communication in quantum teleportation”

Abstract

In this paper, we make a few corrections to a paper by Zha and Ren [Phys. Rev. A 77, 014306 (2008)]. The Zha-Ren protocol for teleportation in principle is equivalent to Rigolin’s protocol [G. RigolinPhys. Rev. A 71, 032303 (2005)] and the associated Comment [F. G. DengPhys. Rev. A 72, 036301 (2005)]. We feel that the transformation operator is not well suited as a criterion for the faithful teleportation, but can be used as a means to transform an arbitrary four-qubit entangled state into a tensor product state of two Bell states. We give all the transformation operators.