This leads us to more radical interpretations like black hole complementarity.

The no cloning theorem prevents us from viewing the holographic principle for black holes as meaning we have two copies of information lying at the event horizon and the black hole interior simultaneously.

2 If we have access to information in a classical sense we can make copies of the information without any theoretical limits. This would allow Alice and Bob to communicate across space-like separations. The Theorem Partial cloning Summary Prerequisites The result pt. Bob will know that Alice has transmitted a '0' if all his measurements will produce the same result otherwise, his measurements will have outcomes +1/2 and −1/2 with equal probability. The no-cloning theorem does not prevent superluminal communication via quantum entanglement, as cloning is a sufficient condition for such communication, but not a necessary one. This theorem essentially states that non-orthogonal states of a closed quantum system cannot be reliably distinguished, and hence cannot be copied. Bob creates many copies of his electron's state, and measures the spin of each copy in the z direction.

To transmit '1', Alice does nothing to her qubit. Alice could send bits to Bob in the following way: If Alice wishes to transmit a '0', she measures the spin of her electron in the z direction, collapsing Bob's state to either or. Assume parts of a maximally entangled Bell state are distributed to Alice and Bob. Nevertheless, consider the EPR thought experiment, and suppose quantum states could be cloned.

The no-cloning theorem does not prevent superluminal communication via quantum entanglement, as cloning is a sufficient condition for such communication, but not a necessary one.

In other words, quantum states cannot be measured reliably.

Similarly, cloning would violate the no teleportation theorem, which says classical teleportation (not to be confused with entanglement-assisted teleportation) is impossible.

In 1995, Shor and Steane revived the prospects of quantum computing by independently devising the first quantum error correcting codes, which circumvent the no-cloning theorem. As such, the cloning operator cannot act. Error correction is vital for practical quantum computing, and for some time this was thought to be a fatal limitation. Ortigoso, Twelve years before the quantum no-cloning theorem, Am. For example, we cannot create backup copies of a state in the middle of a quantum computation, and use them to correct subsequent errors.

The no-cloning theorem prevents us from using classical error correction techniques on quantum states.

No clone theorem