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A new theory “discovers” light in the darkness of the void.

Black holes are regions in spacetime with massive amounts of gravity. Scientists originally believed that nothing could escape the confines of these massive objects, including light.

The exact nature of black holes has been questioned since Albert Einstein’s general theory of relativity led to the possibility of their existence. One of the most famous discoveries was the prediction of the English physicist Stephen Hawking that some particles are actually emitted at the edge of Black hole.

Physicists also discovered how vacuum cleaners work. In the early 1970s, while Hawking was describing how light could escape the gravitational pull of a black hole, Canadian physicist William Unruh suggested that a fast enough photodetector could “see” light in a vacuum.

New research from Dartmouth advances these theories by detailing a method for producing and detecting light that was previously considered unobservable.

“In the proposed experiment, shown here, a postage stamp-sized synthetic diamond film containing nitrogen-based photodetectors is suspended in a supercooled metal box that creates a vacuum. The membrane, which serves as a captive springboard, accelerates at tremendous speeds, producing photons. Credit: LaDarius Dennison / Dartmouth College Animation

Miles Blencoe, Eleanor and A. “We basically produce something from scratch; the idea of ​​that is really cool.

In classical physics, vacuum is the absence of matter, light, and energy. In quantum physics, a void is not empty, but filled with photons that fluctuate in and out of existence. However, it is practically impossible to measure this light.

Part of Einstein’s general theory of relativity, the ‘equivalence principle’, Vincula Hawking’s prediction from Radiación de los agujeros Negros with Unruh’s prediction of aceleración de los fotodetectores que ven la luz. The equivalence says that gravity and acceleration are fundamentally indistinguishable: a person in a windowless elevator and accelerating would not be able to determine if he was under the influence of gravity, inertial force, or de los dos.

So, if the gravity of black holes can create photons in a vacuum, they can also be accelerated.

With the knowledge already showing that it was possible to observe light in a vacuum, the Dartmouth team set out to find a practical way to detect photons.

Myles Blencoe of Dartmouth, Eleanor A. Kelvin Smith, Emeritus Professor of Physics, and Hui Wang, a postdoctoral researcher, describe an experiment that could allow researchers to produce and detect light in a vacuum. Credit: Robert Gill/Dartmouth College

The Dartmouth Research Theory, published in Nature Research’s Communication Physics, predicts that nitrogen-based defects in the accelerating diamond membrane can perform the detection.

In the proposed experiment, a postage stamp-sized synthetic diamond containing nitrogen-based photodetectors was suspended in a supercooled metal box that produced a vacuum. The membrane, which serves as a captive springboard, accelerates at tremendous speeds.

The paper explains that the vacuum photon output produced in the cavity has been collectively optimized and measured, with vacuum photons producing a phase transition from a normal phase to a “reverse phase laser ultra-enhanced type” when the number of detectors exceeds a critical value. .

“The motion of diamonds produces photons,” said Hui Wang, a postdoctoral researcher who wrote the theoretical paper when he was a graduate student at Dartmouth. “Basically, all you have to do is shake something powerful enough to produce entangled photons.”

The Dartmouth paper studies the use of multiple photon detectors (diamond defects) to amplify membrane acceleration and increase detection sensitivity. The diamond’s oscillation also allows the experiment to unfold in a controllable space at intense acceleration speeds.

“Our work is the first to explore what happens when there are several optical accelerometers instead of one,” Blenko said. “We explored the effect of quantum-enhanced amplification to create light out of a vacuum, in which the collective effect of several acceleration detectors is more important than looking at them individually.”

To confirm that the detected photons come from a vacuum and not from the surrounding environment, the team showed that the theory observes “entangled light,” a hallmark of quantum mechanics that cannot come from external radiation.

“The photons detected by the diamond are produced in pairs,” Hoy said. “This production of double and entangled photons is evidence that photons are produced in a vacuum rather than from another source.”

The proposal for observing light in a vacuum does not have immediate applicability, but the research team hopes it will contribute to an understanding of the physical forces that contribute to society in the same way that other theoretical investigations do. In particular, the work may help shed experimental light on Hawking’s predictions of radiation from black holes through the lens of Einstein’s equivalence principle.

“Part of the responsibility and joy of being theorists like us is having ideas,” Blenko said. “We’re trying to show that it’s possible to have that experience, to try something that’s hitherto been very difficult.”

The technical animation produced by the team demonstrates the formation of photons through the experiment. The detected light is at microwave frequency, so it is not visible to the human eye.

Reference: “Coherent amplification of vacuum photon production by a dense cloud from accelerating photodetectors” by Hui Wang and Miles Blencowe, 10 Jun 2021, Communication Physics.
DOI: 10.1038 / s42005-021-00622-3

The research was supported by the National Science Foundation.