Hello, Majorana: Reminding the Higgs That Particle Physics Doesn’t Revolve Around It

There is a delicate symmetry in the world of particle physics. For every particle, there is an antiparticle of the same mass but opposite charge. Antimatter is not just the stuff of science fiction- it is a very real thing, but we can’t run across it when out for a walk. When a particle and its antiparticle meet, they annihilate, releasing photons. Due to CP violation (which we discussed a few years ago), we have an abundance of matter in the universe, but little antimatter.

But what if I told you there was a particle that spit on that symmetry? A particle that is its own antiparticle.

Galleons, meet the Majorana fermion.

Back in the 1930s, a physicist by the name of Ettore (you guessed it) Majorana1 predicted that quantum theory allowed for a special little fermion that hovered right on the border between matter and antimatter, making that single fermion its own particle-antiparticle pair.

Over the years, most predicted particles have been found. Noted exceptions are the attention-whore Higgs boson and the quieter Majorana fermion.

Well, looks like we can check the Majorana fermion off the list, dear galleons, because a group of scientists at TU Delft’s Kavli Institute and the Foundation for Fundamental Research on Matter have found it. Led by nanoscientist Leo Kouwenhoven, the scientists created a rather unique way of finding the elusive Majorana fermion. See, we usually detect particles by smashing beams of protons or protons/anti-protons or what-have-you together in supercolliders. The resulting particle spray hits the detectors and is analyzed for anomalies, which leads to the discovery of new particles. But even the LHC, beast though it may be, isn’t quite sensitive enough to detect the super-elusive Majorana. However, our scientists realized there was another solution: nanostructures.

Kouwenhoven and his team created a nanoscale electrical device out of indium antemonide nanowire,  superconducting niobium contact, and a strong magnetic field:

Between the name of the fermion and the picture of the device created to detect it, I can't help but think that some sort of subatomic symphony was played to find the Majorana. Then again, I've always had a soft spot for correlations between music and physics (re: superstring theory).

Two particles appeared at either end of the device, particles that the team says can only be Majorana fermions. I’m going to trust them, because I’m too tired to slog through the technical specs of the experiment (maybe I’ll get around to it later- if so, I’ll update you with more information on the hows and whys of the Majorana detection).

Beyond the fact that they are interesting and unique particle specimens, Majorana particles are special for a few other reasons. There’s a theory that suggests that dark matter, that unknown quantity in our universe, is comprised of Majorana fermions (though it’s by no means the only, or even most popular, theory surrounding dark matter composition). What’s even more tantalizing about the Majorana fermion is the potential for use in quantum computing. A quantum computer based on Majorana fermions, due to their unique nature, is far more stable than your average quantum computer. It would be quite exciting if the stability of the Majorana fermion helped us move quantum computing out of the realm of theory and into the realm of reality.

Regardless, new particle.

Exciting stuff, my galleons.

1 Okay, I have to add this bit in here because Majorana himself was a rather interesting man. A brilliant Italian physicist, he was drawn to the field from a young age, and his prediction that the Majorana fermion existed arose from a previously unknown solution to the equations from which possible particles are deduced. Indeed, Majorana seemed a force to be reckoned with. He worked with legends like Heisenberg and Bohr. And yet… in 1938, on a boat trip from Palermo to Naple, Majorana disappeared. There are many proposed explanations for his disappearance: he committed suicide, he ran off to a monastery, he was kidnapped/killed to prevent him from working on atomic weaponry, he changed identities and became a beggar, etc. Regardless of all these theories, no one actually knows what happened to him. Majorana was never seen or heard from again.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s