Bizarre Particle's Mass Depends on Travel Direction

2024-12-12

Scientists have unexpectedly discovered a strange quasiparticle, a semi-Dirac fermion, in a ZrSiS material. This particle exhibits a peculiar behavior: it's massless when moving along a specific direction but gains mass when traveling in other directions. This discovery, stemming from research into the properties of quasiparticles within ZrSiS, relates to Einstein's mass-energy equivalence, E=mc². When moving at light speed in a specific direction, the quasiparticle is massless; changing direction and slowing down causes it to gain mass. The finding could potentially lead to novel applications for ZrSiS, similar to those of graphene.