Editing Bell state (section)

=== Quantum teleportation ===
{{Main|Quantum teleportation}}
[[Quantum teleportation]] is the transfer of a quantum state over a distance. It is facilitated by entanglement between A, the giver, and B, the receiver of this quantum state. This process has become a fundamental research topic for quantum communication and computing.  More recently, scientists have been testing its applications in information transfer through optical fibers.<ref>{{Cite journal|last=Huo|first=Meiru|date=19 October 2018|title=Deterministic Quantum Teleportation through Fiber Channels|journal=Science Advances|volume=4|issue=10|pages=eaas9401|doi=10.1126/sciadv.aas9401|pmid=30345350|pmc=6195333|bibcode=2018SciA....4.9401H|doi-access=free}}</ref> The process of quantum teleportation is defined as the following:

Alice and Bob share an EPR pair and each took one qubit before they became separated. Alice must deliver a qubit of information to Bob, but she does not know the state of this qubit and can only send classical information to Bob.

It is performed step by step as the following:

# Alice sends her qubits through a [[Controlled NOT gate|CNOT gate]].
# Alice then sends the first qubit through a [[Hadamard gate]].
# Alice measures her qubits, obtaining one of four results, and sends this information to Bob.
# Given Alice's measurements, Bob performs one of four operations on his half of the EPR pair and recovers the original quantum state.<ref name="Nielsen-2010" />

The following quantum circuit describes teleportation:
[[File:Telep.jpg|center|thumb|Quantum circuit for teleporting a qubit]]