The Bloch sphere is the geometric representation of a two-level quantum system — every point on the sphere corresponds to a pure state, every point inside to a mixed state. Watching a spin precess on the Bloch sphere builds intuition that no equation can replace.

What the Demo Will Show

An interactive 3D Bloch sphere in the browser where the user can:

  • Apply a static field and watch Larmor precession
  • Turn on optical pumping and see the state spiral toward the poles
  • Add relaxation (T₁, T₂) and observe the magnetisation decay
  • Sweep the RF field and find the resonance condition
  • Compare the quantum spin dynamics with the Bloch vector approximation

Applications Context

The same physics drives optically pumped magnetometers (OPMs) used for:

  • MEG — wearable brain imaging with quantum sensors
  • Magnetic anomaly navigation — GNSS-denied positioning using Earth’s crustal field
  • Geophysical surveying — mapping subsurface geological structure

Content pipeline: The interactive demo is planned. The physics engine exists in the lesson code; the browser deployment will use WebAssembly or ClojureScript.

Source: modules/mayapramana/applications.org — quantum magnetometry for brain imaging (288 lines, ~11 KB)