The first 'atom tornado' was formed by spinning helium atoms.

 The lasers could be used to look for subatomic details that aren't visible to the naked eye.

An artist's depiction of a swirling vortex beam. (Image credit: Weiquan Lin via Getty Images)

Physicists have developed the world's first atomic vortex beam, a swirling tornado of atoms and molecules with fascinating features still unknown.

Scientists used the strange rules of quantum mechanics to turn a straight beam of helium atoms into a swirling vortex by passing it through a grating with microscopic openings.

The orbital angular momentum generated by the beam's rotation provides it a new direction to move in, allowing it to function in ways that experts have yet to foresee. Because the electrons and nuclei inside the spiralling vortex atoms spin at different speeds, they believe the atoms' rotation could add more dimensions of magnetism to the beam, as well as other unanticipated consequences.

According to research co-author Yair Segev, a physicist at the University of California, Berkeley, "one possibility is that this might also modify the magnetic moment of the atom," or the intrinsic magnetism of a particle that causes it to operate like a miniature bar magnet.

Negatively charged electrons orbit a positively charged atomic nucleus in the simplified, conventional image of the atom. According to Segev, as the atoms rotate as a whole, the electrons inside the vortex spin faster than the nuclei, "producing different opposing [electrical] currents" as they twist. According to Michael Faraday's renowned rule of magnetic induction, this might result in a slew of novel magnetic effects, including magnetic moments that point through the centre of the beam and out of the atoms themselves, as well as phenomena they can't foresee.

The beam was formed by passing helium atoms through a grid of small openings measuring 600 nanometers in width. Atoms may behave both like particles and tiny waves in the domain of quantum physics, thus the beam of wave-like helium atoms diffracted across the grid, bending so much that it emerged as a vortex that corkscrewed its way through space.

The whirling atoms then hit a detector, which imprinted several beams — diffracted to different degrees to give them different angular momentums — as tiny small doughnut-like rings. Inside the middle three swirls, the scientists discovered even smaller, brighter doughnut rings. Helium excimers — a molecule created when one highly excited helium atom clings to another helium atom — have these telltale marks. (Helium is normally a noble gas that does not attach to anything.)

The quantum mechanical "selection rules" that dictate how the whirling atoms interact with other particles are also changed by the orbital angular momentum imparted to atoms inside the spiralling beam, according to Segev. The scientists will then smash their helium beams against photons, electrons, and atoms of non-helium elements to examine how they react.

If their revolving beam behaves differently, it could be a perfect candidate for a new sort of microscope that can gaze into hitherto unknown subatomic details. According to Segev, the beam could provide additional information on specific surfaces by modifying the image imprinted on the beam atoms that bounce off it.

"I believe that, as is often the case in science, it is a shift of perspective rather than a jump of aptitude that leads to something new," Segev remarked.

Originally Published Here.