Dear Dr. Bennett,

May I ask a question on what you call 'teleportation'.

You wrote at
http://www.research.ibm.com/quantuminfo/teleportation

that "perfect teleportation is indeed possible in principle, but only if the original is destroyed".

On the other hand, I'm flabbergasted form a recent paper by Asher Peres [Ref. 1]: what is teleported *instantaneously* is knowledge, he says. You have to be a ghost to do this miracle, I'm afraid,

http://members.aon.at/chakalov/Peres.html#brain

I really don't know what is destroyed by such instantaneous teleportation of knowledge. Please advise. See also 'loop quantum teleportation' at

http://members.aon.at/chakalov/Frasca.html#NB

and the problems of "quantum computing" with STR,

http://members.aon.at/chakalov/Steane.html#NB

I hope you and Asher will discuss these matters on May 9th, after his talk (12:20 - 1:00),

Charles H. Bennett 60th Birthday Symposium Schedule (May 8-9, 2003)
http://www.research.ibm.com/quantuminfo/chb.html

Please keep me posted.

Regards,

Dimi Chakalov

P.S. BTW your ideas on 'teleportation' make sense to me in the context of Sheldrake's Morphic Field,

http://www.sheldrake.org/faq/answers.html/#Parts

May the Morphic Field be with you on your birthday!

See also my FAQ at
http://members.aon.at/chakalov/faq.html

D.C.
 

Reference

[Ref. 1] Asher Peres, What is actually teleported?
http://xxx.lanl.gov/abs/quant-ph/0304158

"It is a great pleasure to participate in the IBM Symposium honoring the 60th birthday of Charles Bennett.
...

"The notion "quantum state" encapsulates what is known of the preparation of a system [4]. An unknown quantum state is a contradiction in terms, an oxymoron, just as a "research proposal." Enrico Fermi said that when there is no surprise, it's not research.

"Anyway, Alice and Bob are not real people. They are inanimate objects. I have seen an optical bench with a label ALICE near a piece of hardware, and BOB near another one. The hardware knows nothing. What is teleported instantaneously from one system (Alice) to another system (Bob) is the applicability of the preparer's knowledge to the state of a particular qubit in these systems [5]. The preparer whose knowledge is teleported is a real person with a PhD in physics. His name is Chris.
...

"9 EPR vs quantum teleportation

"In the EPR-Bohm scenario [17], Alice and Bob share a pair of spin-1/2 particles in a singlet state. Alice measures a component of her spin, and then she knows instantaneously the corresponding component of Bob’s spin [18], namely Bob's result if he measures (has measured, will measure) the same component of his spin. However, Alice cannot choose the result she obtains.

"In the teleportation scenario, Chris chooses the state of the qubit he prepares near the apparatus called ALICE. He also prepares an EPR pair and places the two entangled spins with ALICE and BOB, far away from each other. Then ALICE is used to measure the two spins in her location so that Chris knows which one of the four possible results was obtained; and then Chris *immediately* knows the state of the spin located at BOB."