SEMI-DIRAC FERMIONS: SCIENCE & TECHNOLOGY

SEMI-DIRAC FERMIONS: SCIENCE & TECHNOLOGY

NEWS: ‘Strange’ particle found to have mass when moving in one direction, not another

 

WHAT’S IN THE NEWS?

Physicists have discovered semi-Dirac fermions, subatomic particles with unique directional mass properties, in the crystalline material zirconium silicon sulphide (ZrSiS). These discoveries challenge the Standard Model and provide fresh insights into the fundamental laws governing the universe.

 

1. Understanding Subatomic Particles

  • Definition and Significance:
  • Subatomic particles are the smallest units of matter and energy.
  • They explain the formation and interactions of all matter in the universe.
  • Main Categories:
  • Fermions: Particles like electrons, protons, and neutrons that form matter.
  • Bosons: Force-carrying particles like photons (light) and gluons (strong nuclear force).

 

2. Types of Fermions

  • Dirac Fermions:
  • Named after Paul Dirac.
  • May or may not possess mass and differ from their antiparticles.
  • Majorana Fermions:
  • Theoretical particles that are their own antiparticles.
  • Neutrinos are hypothesized to belong to this category, though not yet confirmed.

 

3. Challenges in Particle Physics

  • Unanswered Mysteries:
  • Existence and nature of particles responsible for gravity (gravitons).
  • Direct detection of dark matter, which constitutes most of the universe’s mass.
  • Issues with the Standard Model:
  • While it organizes known particles, it fails to explain gravity and dark matter.
  • Particles like Higgs bosons and neutrinos exhibit unexpected masses.

 

4. Discovery of Semi-Dirac Fermions

  • What Are They?:
  • A unique class of particles exhibiting fermionic behavior.
  • Directional Mass: Semi-Dirac fermions have mass in one direction but remain massless in another.
  • Host Material:
  • Found in zirconium silicon sulphide (ZrSiS), a crystalline compound.
  • Behavior:
  • Display unusual electronic and magnetic properties under specific conditions.

 

5. Role of Condensed Matter Physics

  • Enabling Discovery:
  • Unlike large-scale particle colliders, condensed matter physics uses smaller, controlled experiments.
  • Materials as Hosts:
  • Crystals like ZrSiS and graphene act as laboratories for discovering exotic particles.
  • Advantages:
  • Easier and more cost-effective than high-energy collider experiments.

 

6. Implications and Future Research

  • Expanding the "Particle Zoo":
  • Semi-Dirac fermions add to the growing catalog of subatomic particles.
  • Their study bridges gaps in our understanding of the universe.
  • ZrSiS Exploration:
  • Researchers aim to uncover other unique properties of this material.
  • Revolutionizing Physics:
  • These findings bring us closer to resolving mysteries like dark matter and quantum gravity.

 

Source: https://www.thehindu.com/sci-tech/science/particle-found-to-have-mass-when-moving-in-one-direction-not-another/article69092319.ece#:~:text=Majorana%20fermions%20are%20fermions%20that,suspected%20to%20be%20Majorana%20fermions).