Magnet 900,000 times stronger than Earth reveals directional mass particles
The team used a hybrid magnet, generating a field 900,000 times stronger than Earth’s, the most powerful sustained field worldwide.
In a significant advancement, researchers have discovered a group of particles, called quasiparticles, that have mass in one direction but are massless in another.
The quasiparticle called a semi-Dirac fermion, which was first predicted 16 years ago, has been now found inside a semi-metal crystal called ZrSiS.
The discovery was made during experiments conducted at Florida’s National High Magnetic Field Lab, using a hybrid magnet 900,000 times stronger than Earth’s magnetic field.
Scientists at Penn State and Columbia University say this discovery could lead to advances in technologies like batteries and sensors.
“We weren’t even looking for a semi-Dirac fermion when we started working with this material, but we were seeing signatures we didn’t understand — and it turns out we had made the first observation of these wild quasiparticles that sometimes move like they have mass and sometimes move like they have none,” said Yinming Shao, assistant professor of physics at Penn State and lead author on the paper, in a statement.
Mass direction paradox
Particles can sometimes behave as if they have no mass when their energy comes entirely from motion, making them pure energy moving at the speed of light. For example, photons, or light particles, are massless because they travel at light speed.
According to Einstein’s theory of special relativity, anything moving at the speed of light cannot have mass. However, in solid materials, the collective behavior of many particles, called quasiparticles, can behave differently. This unique behavior can result in particles having mass in one direction only.