We explore the mechanism of quantum teleportation by analyzing the weak
measurement statistics post-selected by the result of the Bell measurement for
the joint system composed of the input A and the spatially separated output B.
It is shown that the weak measurement statistics observed before the Bell
measurement includes correlations which relate every physical property in the
input A to a corresponding physical property in the output B. The Bell
measurement thus identifies the accidental relation between A and B already
present in the quantum fluctuations of the input state. Significantly, this
relation applies to all physical properties equally, and is completely
independent of the input state. Teleportation therefore copies all physical
properties of input system A to output system B, irrespective of whether the
input state is an eigenstate of the property or not.Comment: 14 pages, including 3 figures, clarification of the relation between
weak measurement results and transient states. Final version for publication
in J. Phys.