A team of physicists from the University of Edinburgh’s School of Physics and Astronomy used mathematical calculations to show that quantum communication across interstellar space should be possible. Their paper, published in the journal Physical Review D, describes their calculations and the possibility that aliens could use this signal to communicate with us.
For the past few years, scientists have been investigating the possibility of quantum communication as a highly secure form of information transmission. Previous research has shown that it is nearly impossible to intercept quantum messages without being detected. In the latest analysis, the researchers wondered whether similar communication might be possible in interstellar space.
To find out, they used mathematics to characterize the motion of X-rays in a medium, such as X-rays propagating between stars. More specifically, they wanted to see if their calculations could show the degree of decoherence that could occur on such a journey.
Quantum particles lose some or all of their unique properties when interacting with obstacles in their path — in fact, they are very fragile. Such events are known as decoherence, and engineers working on building quantum networks have been figuring out how to overcome it. Previous research has shown that the space between stars is very clean. But is it clean enough for quantum communication? Mathematical calculations show that it is. Space is so clean that X-ray photons can travel hundreds of thousands of light-years without suffering from decoherence — which includes gravitational interference from celestial bodies. The paper points out that the optical band and the microwave band can work equally well.
The researchers point out that since quantum communication can span the galaxy if there are other intelligent beings in the galaxy, they may already be trying to use this technology to communicate with us, and we can start looking for them. They also suggest that quantum teleportation across interstellar space should also be possible.
https://phys.org/news/2022-07-mathematical-quantum-interstellar-space.html
