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Demonstration of ‘weird quantum effect’ that transforms the matter to invisible

Demonstration of ‘weird quantum effect’ that transforms the matter to invisible

Exhibition of decades old weird quantum

A strange quantum effect that has been predicted for decades has finally been proven. According to quantum theory, if a cloud of gas is sufficiently cold and dense enough, it will become invisible.

Lasers were employed by scientists at the Massachusetts Institute of Technology (MIT) to squeeze and cool lithium gas to densities and temperatures low enough to scatter less light. It becomes absolutely undetectable if they can cool the cloud to absolute zero (-459.67 degrees Fahrenheit, or -273.15 degrees Celsius).

The strange effect is the first known example of Pauli blocking, a quantum mechanical phenomena.

“What we’ve found is one very particular and basic sort of Pauli blocking,” said senior author Wolfgang Ketterle, an MIT physics professor, “which prevents one atom from doing what all atoms would naturally do, which is scatter light.” He went on to say that this is the first clear observation of the impact and that it reveals a novel physics phenomena.

The novel method could be used to create light-suppressing materials for quantum computers to prevent data loss.

Further Observations

Atoms in a gas cloud usually have a lot of room to bounce around in. Even though they are fermions confined by the Pauli Exclusion Principle, there are enough unoccupied energy levels to jump into for the principle to not block their travel considerably.

Any atom that comes into contact with a photon, or light particle, in a moderately heated gas cloud will be able to interact with it. It will absorb the photon’s entering momentum, recoil to a different energy level, and scatter it away.

When a gas is cooled down, however, a new storey emerges. The atoms now lose energy, occupying all of the lowest accessible states and generating a Fermi sea, which is a sort of matter. The particles are now caged in by one another, unable to travel up or down to higher or lower energy levels.

They’re stacked in shells like sitting concertgoers in a sold-out auditorium at this stage, with nowhere to flee if hit, according to the experts. They’re so dense that the particles can’t interact with light anymore. The light that is sent in is obstructed by Pauli and will simply pass through.

“An atom can only scatter a photon if it can absorb the force of its kick, which it can do by shifting to a different chair,” Ketterle explained. “It loses its power to absorb the kick and scatter the photon if all other chairs are filled. As a result, the atom turns transparent.”


However, achieving this state in an atomic cloud is extremely challenging. It requires not only extremely low temperatures, but also the atoms to be crushed in order to record densities. It was a delicate process, so the researchers exploded their gas with laser after holding it inside an atomic trap.

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