Delft University of Technology researchers have successfully transmitted quantum information over a core network. This is the first of its kind and a major step towards a quantum internet. This achievement is made possible by greatly increasing the quantum memory and improving the quality of the quantum link between the three nodes of the network. The ability to transmit quantum information between network nodes is what gives the quantum Internet of the future its power. This will open the door to a wide range of applications, including secure sharing of private information, linking multiple quantum computers to boost processing power, and using high-resolution, interconnected quantum sensors.
Small quantum processors form the nodes of such a network. It is not easy to send quantitative information through these processors. One option to do this is to connect quantum qubits using particles of light. But due to the inevitable losses of fiberglass cables, the light particles are unlikely to reach.
Teleportation is a more efficient approach to transmitting quantum data. The quantum teleportation protocol gets its name from its resemblance to sci-fi teleportation: quantum bits disappear from the transmitter side and reappear on the receiver side.
Researchers working at QuTech – a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research (TNO) – have published their findings in the journal Nature.
The researchers used an intermediate node called “Bob” to transfer quantum bits from the “Charlie” node to the “Alice” node.
The process is explained in a video shared on QuTech’s Twitter page.
A report states that there are three steps to teleportation. First, the teleporter must create a tangled state between Alice and Charlie. Although Alice and Charlie are not physically related, they are related to Bob. Alice and Bob achieve this by connecting their wizards together. After that, Bob and Charlie became entangled. Bob then transmits the tangle as it was by performing a specific measurement in his processor. The teleporter is now ready to deploy, and Alice and Charlie are getting tangled up.
The ‘message’ – the quantum bit – that will be transmitted in the second stage is generated. This quantitative data has been prepared by Charlie.
The third step is the actual teleportation from Charlie to Alice. For this purpose, Charlie uses his quantum processor and half of his entangled state to make a common measurement with the message (Alice owns the other half). As a result of this analogy, the information on Charlie’s side disappears and immediately reappears on Alice’s side.
You may think that everything is over, but this is far from reality. In fact, the quantum bit was encrypted during transmission, with the result of Charlie’s measurement determining the key. As a result, Charlie sends the measurement result to Alice, who then performs the appropriate quantum operation to decode the quantum bit. The quantum information is ready to use after Alice has completed the correct operation.