EQMResearch group
Level 1 · Foundations

Spin

↑ / ↓

Every electron carries a tiny intrinsic magnet. Pointing them up or down is the seed of all the magnetic patterns in this project.

Build on:Atoms & electrons

The tiny built-in magnet

Every electron carries an intrinsic angular momentum called spin. Despite the name, nothing is actually rotating — it is a purely quantum-mechanical property with no classical counterpart. Two things matter for us:

  • The spin can take only two values along any axis we measure, often written ↑ and ↓.
  • Spin makes the electron behave like a tiny bar magnet. Add up many electrons in a crystal and you can get a bulk magnetic response.

From a single arrow to a chain

The simulator stores its magnetic state as a 1D string of these arrows, one per atomic layer. Click below to flip a few:

AFM 30Mixed 0FM 0
Click cells to flip them. Below the spins, the colored strip shows the local magnetic phase the simulator infers — see the pages on AFM, FM, and Mixed for what those colors mean.

How those arrows arrange themselves between neighboring layers is what makes a material ferromagnetic, antiferromagnetic, or something in between.

Key takeaways
  • Spin is a quantum property; treat it as an unbreakable ↑/↓ arrow.
  • The whole magnetism story in this app is "what pattern of arrows?".
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