Quantum Spin Ice

Particles with the quantum property called spin, illustrated by the blue arrow, can’t agree on an orientation in a type of material called quantum spin ice. Elia Maru Studio/Science Source

The fine-structure constant α is of dimension 1 (i.e., it is simply a number) and very nearly equal to 1/137. It is the "coupling constant" or measure of the strength of the electromagnetic force that governs how electrically charged elementary particles (e.g., electron, muon) and light (photons) interact.

In English, the FSC is the basis for life as we know it.

The fine-structure constant is about 10 times its normal value in a type of material called quantum spin ice, physicists calculate in the Sept. 10 Physical Review Letters. The new calculation hints that quantum spin ice could give a glimpse at physics within an alternate universe where the constant is much larger.

With an influence that permeates physics and chemistry, the fine-structure constant sets the strength of interactions between electrically charged particles. Its value, about 1/137, consternates physicists because they can’t explain why it has that value, even though it is necessary for the complex chemistry that is the basis of life (SN: 11/2/16).

If the fine-structure constant throughout the cosmos were as large as the one in quantum spin ices, “the periodic table would only have 10 elements,” says theoretical physicist Christopher Laumann of Boston University. “And it probably would be hard to make people; there wouldn’t be enough richness to chemistry.”

It's all about geometry yet again.

In quantum spin ices, particles (black dots) are located at the corners of an array of pyramids (red). Normally, the spins of the particles (green arrows) arrange so that two are pointing into the pyramid and two out. If that rule is broken, as illustrated, quasiparticles called spinons (orange and blue) form.

S.D. Pace ET AL/PRL 2021

The issue now is, can researchers actually create this most exotic of materials because if they can, the notion of existence being a multiverse construct may actually be proven to be true.