Super-cooling radioactive atoms could produce a laser-like neutrino beam, according to a duo of physicists from MIT and the University of Texas at Arlington. As an example, the authors calculated that such a neutrino laser could be realized by trapping 1 million atoms of rubidium-83. Normally, the radioactive atoms have a half-life of about 82 days, meaning that half the atoms decay, shedding an equivalent number of neutrinos, every 82 days. They show that, by cooling rubidium-83 to a coherent, quantum state, the atoms should undergo radioactive decay in mere minutes.
B.J.P. Jones & J.A. Formaggio devise an idea for a laser that shoots a beam of neutrinos. Image credit: Gemini AI.
“In our concept for a neutrino laser, the neutrinos would be emitted at a much faster rate than they normally would, sort of like a laser emits photons very fast,” said Dr. Ben Jones, a researcher at the University of Texas at Arlington.
“This is a novel way to accelerate radioactive decay and the production of neutrinos, which to my knowledge, has never been done,” added MIT Professor Joseph Formaggio.
Several years ago, Professor Formaggio and Dr. Jones separately considered a novel possibility: what if a natural process of neutrino production could be enhanced through quantum coherence?
Initial explorations revealed fundamental roadblocks in realizing this.
Years later, while discussing the properties of ultracold tritium they asked: could the production of neutrinos be enhanced if radioactive atoms such as tritium could be made so cold that they could be brought into a quantum state known as a Bose-Einstein condensate?
They also wondered, if radioactive atoms could be made into a Bose-Einstein condensate, would this enhance the production of neutrinos in some way? In trying to work out the quantum mechanical calculations, they found initially that no such effect was likely.
“It turned out to be a red herring — we can’t accelerate the process of radioactive decay, and neutrino production, just by making a Bose-Einstein condensate,” Professor Formaggio said.
Several years later, Dr. Jones revisited the idea, with an added ingredient: superradiance — a phenomenon of quantum optics that occurs when a collection of light-emitting atoms is stimulated to behave in sync.
In this coherent phase, it’s predicted that the atoms should emit a burst of photons that is superradiant, or more radiant than when the atoms are normally out of sync.
The physicists proposed that perhaps a similar superradiant effect is possible in a radioactive Bose-Einstein condensate, which could then result in a similar burst of neutrinos.
They went to the drawing board to work out the equations of quantum mechanics governing how light-emitting atoms morph from a coherent starting state into a superradiant state.
They used the same equations to work out what radioactive atoms in a coherent Bose-Einstein condensate state would do.
“The outcome is: You get a lot more photons more quickly, and when you apply the same rules to something that gives you neutrinos, it will give you a whole bunch more neutrinos more quickly,” Professor Formaggio said.
“That’s when the pieces clicked together, that superradiance in a radioactive condensate could enable this accelerated, laser-like neutrino emission.”
To test their concept in theory, the researchers calculated how neutrinos would be produced from a cloud of 1 million super-cooled rubidium-83 atoms.
They found that, in the coherent Bose-Einstein condensate state, the atoms radioactively decayed at an accelerating rate, releasing a laser-like beam of neutrinos within minutes.
Now that they have shown in theory that a neutrino laser is possible, they plan to test the idea with a small tabletop setup.
“It should be enough to take this radioactive material, vaporize it, trap it with lasers, cool it down, and then turn it into a Bose-Einstein condensate,”Dr. Jones said.
“Then it should start doing this superradiance spontaneously.”
The pair acknowledge that such an experiment will require a number of precautions and careful manipulation.
“If it turns out that we can show it in the lab, then people can think about: Can we use this as a neutrino detector? Or a new form of communication? That’s when the fun really starts,” Professor Formaggio said.
The team’s paper was published today in the journal Physical Review Letters.
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B.J.P. Jones & J.A. Formaggio. 2025. Superradiant Neutrino Lasers from Radioactive Condensates. Phys. Rev. Lett 135, 111801; doi: 10.1103/l3c1-yg2l
