Three-dimensional skyrmion: Scientists observe theoretical particle for first time


Forty years after scientists first theoretically predicted the existence of a three-dimensional skyrmion, scientists have observed the particle in the lab.

The particle, observed cold quantum gas, isn’t a normal particle composed of electrons, protons and electrons. It is a quantum particle, the energy signature created by the interactions between a particle and the surrounding system.

In this instance, the quantum particle is a tangled knot of magnetic moments in the quantum gas.

“The quantum gas is cooled down to a very low temperature where it forms a Bose-Einstein condensate: all atoms in the gas end up in the state of minimum energy,” David Hall, a professor of quantum physics at Amherst College, said in a news release. “The state does not behave like an ordinary gas anymore but like a single giant atom.”

To create the unique quantum particle, scientists applied a natural magnetic field to the supercooled gas, causing each of the atoms’ polarized spins to point upward in the same direction. When the magnetic field is suddenly altered to create its originating point at the point the field previously vanished, the atoms begin to take on a new polarized spin direction.

The sudden change causes the polarized spins near the altered magnetic field origin to point to spin in all possible directions. These spins form a tangled knot, with linked loops spinning toward a fixed location. Alterations of the applied magnetic fields can tighten or loosen the knot but not break it.

Like a charged particle in a magnetic field, the quantum knot effects the surrounding gas condensate, causing a knotted artificial magnetic field to form. The dynamic resembles the behavior of ball lightning, a ball of plasma science believe is composed of tangled electric currents.

“It is remarkable that we could create the synthetic electromagnetic knot, that is, quantum ball lightning, essentially with just two counter-circulating electric currents,” said lead researcher Mikko Möttönen, a physicist at Aalto University in Finland. “Thus, it may be possible that a natural ball lighting could arise in a normal lightning strike.”

Scientists aren’t yet sure if they can use the method to create ball lightening, but the findings — published in the journal Science Advances — could be used to create a ball of plasma that doesn’t break apart. Such a breakthrough could inspire energy-efficient fusion reactors.