Scientists make quantum leap in data transmission
A group on researchers in China have found a way of successfully sending signals through quantum networks at greater distances than ever before
By Jane McFadyen
Scientists in China have made a breakthrough in the task of sending data through free space (vacuum or air) using quantum teleportation. The group, led by quantum scientist Juan Yin, has successfully sent a signal between a transmitter and receiver set at 97km apart.
The problem with sending such signals over large distances is that photons are absorbed into cable networks, which means that small signals – with few photons – cannot be successfully sent and received.
An article in the UK’s Wired magazine describes how the team has been focusing on quantum networks, which generally only use small quantities of ‘entangled’ photons. Entanglement refers to the close relationship pairs of photons achieve in quantum physics. Data sent via this method can sometimes be as small as one single photon.
The researchers have been working on transmitting data through the air as it means that fewer photons are lost in transmission. The difficulty until now has been the ability to perfectly align transmitters and receivers over large distances, and the fact that atmospheric activity can interfere with the signal.
To overcome this, the team has developed a high accuracy pointing and tracking system which it demonstrated across a lake. They also were able to transmit to two receivers placed 101.8km apart from a point roughly halfway between them.
The means of transmission is by laser and at the moment the technology only works at night. However, the scientists are hopeful that their work could be adapted for use in ground-to-satellite quantum communication in the future.