Scientists have observed a unique particle that moves easily one way, yet resists at 90 degrees. These semi-Dirac fermions were observed using their energy signature in a topological metal. Particles ...

For the first time, scientists have observed a collection of particles, also known as a quasiparticle, that's massless when moving one direction but has mass in the other direction. The quasiparticle, ...

The quasiparticle, called a semi-Dirac fermion, was first theorized 16 years ago, but was only recently spotted inside a crystal of semi-metal material called ZrSiS Credit: Yinming Shao / Penn State ...

Strange particles that have mass when moving one direction but no mass when moving in another were first theorised more than a decade ago. Now, these mass-shifting particles have been glimpsed in a ...