tl;dr by ChatGPT:
Scientists have discovered a quasiparticle, the semi-Dirac fermion, which behaves unusually by having mass in one direction but being massless in another. Found in a ZrSiS crystal at extremely low temperatures, this particle challenges conventional physics. Researchers used magneto-optical spectroscopy and strong magnetic fields to observe it. The discovery opens new possibilities in quantum physics and electronics, though many questions remain unanswered.
Deutsch:
Wissenschaftler haben ein Quasiteilchen, das semi-Dirac-Fermion, entdeckt, das in eine Richtung masselos ist, in die andere jedoch Masse hat. Es wurde in einem ZrSiS-Kristall bei extrem niedrigen Temperaturen gefunden. Mithilfe von Magneto-Optischer Spektroskopie und starken Magnetfeldern konnte dieses ungewöhnliche Verhalten beobachtet werden. Die Entdeckung eröffnet neue Möglichkeiten in der Quantenphysik, wirft aber noch viele Fragen auf.
I do not understand this, so I’ll joke:
We should find out which direction is the common “massfull” direction, and call that “Universal Up.”
Regrettably, most of my mass is in a direction I would have to call, “down”…
(I don’t understand it either, so I’ll be self-deprecating!)
Interesting, but I do think it’s important to note for the layperson that these aren’t real particles, no? They are groups that appear to change their emergent group property. That’s not the same as saying a particle is actually massless in one direction through a crystal lattice.