# Quantum Teleportation¶

Quantum teleportation is a method for transmitting the information of a qubit from one location to another. The process relies on a previously shared entangled state between the two locations, and classical communication.

## Overview¶

In the canonical description of quantum teleportation [1] [2] two parties (Alice and Bob) are trying to transmit a state from one to another. They start with an Alice having half of an entangled bell pair (Bob having the other half) and Alice with a third qubit that she would like to transmit to Bob. Alice then entangles the third qubit with her Bell pair qubit, measures both her qubits, and sends the measurement result $$\{0, 1\}^{2}$$ to Bob. Bob uses the classical information from Alice to fix up his state and now has his qubit in the state of Alice’s original qubit she wanted to transfer.

Given that Alice’s data qubit is labeled 0 and the Bell pair qubits are labeled 1 and 2 (Bob having the qubit labeled 2), a Quil program performing the transfer is as follows:

CNOT 0 1
H 0
MEASURE 0 [0]
MEASURE 1 [1]
JUMP-UNLESS @ NOX [1]
X 2
LABEL @NOX
JUMP-UNLESS @NOZ [0]
Z 2
LABEL @NOZ


The Bell state preparation can be prepended to the above Quil with:

H 1
CNOT 1 2


## Teleportation in pyQuil¶

We have included pyQuil code that programatically generates a teleportation program between any two qubits using one ancilla qubit. The ancilla qubit is the piece of the Bell pair that Alice holds. Check the teleportation.py source code for examples.

## Source Code Docs¶

Here you can find documentation for the different submodules in teleport.

### grove.teleport.teleportation¶

References

 [1] Nielsen, Michael A., and Isaac L. Chuang. Quantum Computation and Quantum Information. Cambridge University Press, 2010.
 [2] Wikipedia contributors. “Quantum teleportation.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 4 Jan. 2017. Web. 4 Jan. 2017.