Deletion of imperfect cloned copies
Satyabrata Adhikari, Binayak Samadder Choudhury · Journal of Physics A Mathematical and General · 2004
In this work, we design a deleting machine and show that, for some given condition on machine parameters, it gives a slightly better result than the Pati–Braunstein (PB) deleting machine (2000 Nature 404 164, 2001 Preprint quant-ph/0007121). Also it is shown that for some particular values of the machine parameters it acts like the PB deleting machine. We also study the combined effect of a cloning and deleting machine, where first the cloning is done by some standard cloning machines such as Wootters–Zurek (1982 Nature 299 802) and Buzek–Hillery (1996 Phys. Rev. A 54 1844) cloning machines and then the copy mode is deleted by the PB deleting machine or our prescribed deleting machine. We then examine the distortion of the input state and the fidelity of deletion.