In a pair of papers published in journal physical review letterA team of MIT physicists has shown that neutrino lasers, a concept proposed just a year ago, cannot actually be built, no matter how advanced the technology.
In 2025, BJP Jones and JA Formaggio came up with the idea of a laser that fires a beam of neutrinos.
The idea of a neutrino laser, proposed by Professor Joe Formaggio of MIT and Dr. Ben Jones of the University of Texas at Arlington, was sophisticated in its ambition.
If a cloud of radioactive atoms were cooled to nanokelvin temperatures (one billionth of the cold in interstellar space), the atoms would settle into a Bose-Einstein condensate, a strange quantum state in which they function as a single, synchronous entity.
In this state, the physicists proposed, the radioactive decay of the atom would be dramatically accelerated, and the neutrinos it would emit as byproducts would be emitted in a narrow, laser-like beam, dramatically shortening its radioactive half-life in the process.
But according to MTI Professor Wolfgang Ketterle, a Nobel Prize winner who co-discovered Bose-Einstein condensates in 1995, this idea is too good to be true.
MIT physicists Hanzhen Lin and Yu-Kun Lu collaborate with Professor Ketterle present A two-part analysis demonstrating the neutrino laser concept; Similar proposal for gamma raysis physically and fundamentally impossible.
Neutrinos are emitted with about a million times more energy than the visible photons used in regular lasers. This means that the ejected atoms recoil at speeds equivalent to Mach 10, fast enough to essentially disappear from the condensate almost instantly. This leaves no time for the kind of quantum “imprint” needed for the amplification effect.
“As long as the recoil atoms remain within the condensate, we can make the condensate superradiant,” says Ketterle.
“But when a neutrino is emitted at a million electron volts, the atom recoils at a speed equivalent to Mach 10, faster than a fighter jet. This is so fast that the atom annihilates almost instantly.”
Even in an ideal scenario in which traces could form, researchers say Found It works in the opposite direction. Rather than telling the condensate to emit the next neutrino in the same direction, it sends the opposite signal, preventing the beam from building up.
The researchers trace this inverse correlation to the fact that neutrinos are fermions, a type of particle that contains electrons and behave fundamentally differently than the photons that make superradiant lasers possible.
“These two papers are like punch one and punch two,” Professor Ketterl said.
“The papers would have rejected the proposal.”
“When new ideas like the ones we proposed are shared, it is the community’s duty to vet them,” Professor Formaggio says.
“This is the scientific process, and it was great to see that our paper actually generated a lot of thinking beyond our initial concepts, and we think that’s going to continue.”
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Lu Yukun others. 2026. A superradiant neutrino laser is fundamentally impossible. Physics. pastor rhett 137, 101804;doi: 10.1103/8x7k-rwx2
Lin Hangzhen others. 2026. Can Bose-Einstein condensates promote radioactive decay? Physics. pastor rhett 137, 101805;doi: 10.1103/rnx6-wqpf
Source: www.sci.news
