Physicists have successfully distributed ‘entanglement’ for the first time in a way that could lead to long-distance quantum communications. It could also lead to scalable quantum networks and even a quantum internet.
Caltech Valentine Professor of Physics H. Jeff Kimble and his colleagues have devised a crucial building-block of a “quantum repeater.” The team has demonstrated a way to create a channel segment capable of distributing quantum entanglement over distances.
This division of material systems into segments and storage of entanglement is necessary for long-distance quantum communications to take place. It is published in the April 5 online publication of Science Express.
Julien Laurat, a postdoctoral scholar in physics and one of the authors of the paper said,
This work provides a first primitive version of a quantum repeater segment. It opens an avenue for further investigations into this promising and new quest of large-scale networks where the currency of the realm is no longer classical information but rather quantum information.
The experiment involves two quantum nodes separated by 3 meters. Each of these nodes are formed by two atomic ensembles — clouds of about 100,000 cooled cesium atoms — separated by 1mm. With real-time control of the quantum states, entanglement is generated and stored into the atoms playing the role of a quantum memory. It is finally converted to photons on demand.
