In a proof-of-concept experiment, a group of Chinese researchers from the Shanghai Jiao Tong University had succeeded in sending information between entangled particles across a 3.3-metre long tank filled with seawater. This is the first time such a feat has been achieved.
Researchers behind the experiment claim they should be able to extend the range of transfer close to 900 metres in future attempts.
One of the key advantages of sending information in such a manner is that it becomes impossible to hack – at least to anyone who’s not capable of circumventing the laws of physics themselves, that is.
While quantum communication has already been proven to work by a number of experiments done in the past – “teleporting” data across vast distances through optical fibre and even open space – this is the first instance where it has been achieved in water.
The thing to remember here is that beaming anything through water is exceedingly difficult due to its scattering effect, which makes the experiment even more impressive.
To create a pair of entangled photons, the researchers shot a beam of light through a crystal, resulting in photons that exactly mirrored each other in terms of polarisation.
When placed in a tank with water taken from the Yellow Sea, the particles were shown to be able to accurately communicate with each other more than 98 percent of the time.
“Our results confirm the feasibility of a seawater quantum channel, representing the first step towards underwater quantum communication,” the researchers said in a paper published in the journal The Optical Society.
The next step will be to have the experiment replicated by other teams around the world and to figure out whether it is, in fact, possible to extend the range of data transfer, as well as to replicate the same result in open waters.
Even though the Jiao Tong University team is optimistic that information could eventually be communicated at a distance of around 885 metres, other scientists claim the limit might actually be closer to only 120 meters, owing to the fact that ocean water is light-absorbent.
Whichever turns out to be the case in the end, with the first experiment successfully completed, it shouldn’t be long before we know.