1107.0934 (Giuseppe Castagnoli)

Probing the mechanism of the quantum speed-up by time-symmetric quantum
mechanics    [PDF]

Giuseppe Castagnoli

The time-symmetric representation of a quantum algorithm highlights the quantum correlation existing between the algorithm's input (the problem chosen by Bob) and output (the solution found by Alice). Because of it, all is as if Alice, by reading the solution at the end of the algorithm, contributed to the initial choice of Bob. This quantum retroaction of the output on the input is what allows the quantum algorithm to build a stronger than classical input-output correlation, in fact the quantum speed-up.

View original: http://arxiv.org/abs/1107.0934