this post was submitted on 16 Dec 2024
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2024-11-11

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Summary

Scientists have discovered semi-Dirac fermions, particles that bizarrely gain or lose mass depending on the direction they travel.

Found in the semi-metal material ZrSiS, these quasiparticles are massless when moving at light speed in one direction but gain mass when slowing down in another, due to resistance within the material’s electronic structure.

This behavior, tied to Einstein’s E=mc², was unexpected and may lead to applications similar to graphene.

Researchers are now studying the unexplained quantum interactions behind this phenomenon, published in Physical Review X.

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[–] [email protected] 7 points 22 hours ago (2 children)

and may lead to applications similar to graphene.

Graphene has applications now?

[–] [email protected] 3 points 17 hours ago

Surprisingly, I just read it actually does, and quite a few. None revolutionary and eye-catching like everybody hoped, but apparently, most of us has graphene in our smartphones, for example. I don't remember specifics, I can try to look for the article where I read it, if you want very much.

[–] [email protected] 7 points 22 hours ago

Yes; theoretical ones.

[–] [email protected] 62 points 1 day ago* (last edited 1 day ago) (3 children)

When the quasiparticles travel along one dimension inside the ZrSiS crystals, they do so at the speed of light and are therefore massless. But as soon as they try to travel in a different direction, they hit resistance, slow down and gain mass.

Sounds more like a property of the material than the particle.

Edit: did a little reading. It's not even a real particle, it's a quasi-particle, which apparently means it's a general description of a group of particles.

[–] [email protected] 3 points 17 hours ago

I think a quasi-particle is more like a phenomenon that can mathematically be described in a way a particle would be, rather than just a group of particles. After all, holes in semiconductors are quasiparticles caused by a lack of real particles.

Admittedly, I know very little about quasi-particles.

[–] [email protected] 6 points 20 hours ago

Yup! PBS Spacetime has a nice video on quasi-particles, and how they are pretty much as "real" as protons and neutrons!

[–] EleventhHour 6 points 1 day ago

That’s even crazier

[–] [email protected] 7 points 1 day ago
[–] aeronmelon 4 points 1 day ago

Did anyone bother asking the quasi-particles which direction they want to go?

[–] [email protected] 3 points 1 day ago

Has anyone considered that obviously this particle has been observed moving to and from various kebab shops and other eateries?

[–] spittingimage 4 points 1 day ago

I wonder what cool things we can do with this effect.

[–] randon31415 0 points 1 day ago (1 children)

When I'm driving my car down a street - in one direction it moves without loosing much momentum, but in another direction at a 90 degree angle, my car tends to lose a lot of momentum. Also, it is impossible to move in the z-direction without having a confederate flag on the top of the car and being chased by a sheriff in the deep south.

[–] homesweethomeMrL 1 points 1 day ago

Ah. The Roscoe Theorem.