Overview

• Researchers at Penn State and Columbia University identified semi-Dirac fermions in zirconium silicon sulfide (ZrSiS) crystals, marking the first observation of this unique quasiparticle.
• Semi-Dirac fermions exhibit massless behavior when moving in one direction but gain mass when traveling perpendicularly, a phenomenon predicted over a decade ago.
• The discovery was made using magneto-optical spectroscopy under extreme conditions, including near-absolute-zero temperatures and powerful magnetic fields, at the National High Magnetic Field Laboratory in Florida.
• ZrSiS, a layered material similar to graphite, could potentially be exfoliated into thin sheets for applications akin to graphene, with possible uses in batteries, sensors, and advanced materials.
• While the findings align with theoretical predictions, researchers note that many aspects of the observed behavior remain unexplained, leaving room for further investigation.