The Unruh effect is something that we are used to seeing in some films in which spaceships capable of reaching a speed close to the speed of light or going even further appear in an instant, as in the saga of films and series “Star Trek ” with his famous USS Enterprise or in “Star Wars” and his iconic Millennium Falcon.
It was mathematically described by physicists William George Unruh, Stephen Fulling and Paul Davies between 1973 and 1976. Hence, it is also known as the Fulling-Davies-Unruh effect, in honor of the three physicists who initially proposed it. This effect has to do with quantum interactions between accelerated matter and quantum fluctuations within the vacuum of empty space. But it has never been recreated in a laboratory environment because the probability of seeing the effect is infinitesimally small.
However, a team of researchers from MIT and the University of Waterloo believe they have found a way to significantly increase the probability of observing the Unruh effect, according to their new work published in the journal Physical Review Letters.
The scientists propose as an alternative to stimulate the phenomenon in a very particular way that enhances the Unruh effect while suppressing other competing effects . If it can be done in a practical experiment, this new approach could greatly increase the probability of observing the elusive effect.
The Unruh effect is predicted to occur spontaneously in a vacuum
Instead of waiting longer than the age of the universe for an accelerated particle to produce a warm glow as the Unruh effect predicts, the approach would reduce that wait time to a few hours by adding light to the entire scene, an approach known as stimulation.
“Now at least we know there is a chance in our lifetimes that we might see this effect,” said Vivishek Sudhir, an assistant professor of mechanical engineering at MIT and co-author of the paper. “It’s a difficult experiment and there’s no guarantee we can do it, but this idea is our closest hope.”
“There is a close connection between the Hawking effect and the Unruh effect: they are exactly the complementary effect of each other ,” says Sudhir, who adds that if one were to look at the Unruh effect, “you would have observed a mechanism that is common to both effects.” When you add photons to the field, you’re adding ‘n’ times more of those fluctuations than this half-photon that’s in a vacuum, so if you speed through this new state of the field, I’d expect to see effects that scale ‘n’ times as well. what I would see only with emptiness”.
By making all other effects transparent, researchers might have a better chance of measuring photons or thermal radiation coming from the Unruh effect alone, as physicists predicted all those years ago.
“Now we have this mechanism that seems to statistically amplify this effect through stimulation,” says Sudhir. “Given the 40-year history of this problem, now, in theory, we have solved the biggest bottleneck .”
Referencia: Barbara Šoda, Vivishek Sudhir, Achim Kempf. Acceleration-Induced Effects in Stimulated Light-Matter Interactions. Physical Review Letters, May 2022; 128 (16) DOI: 10.1103/PhysRevLett.128.163603
