Alkali-vapor magnetometers
Spin-polarized atomic vapor precesses in magnetic fields.
$$\omega_L=\gamma B$$
Physical intuition
Spin-polarized atomic vapor precesses in magnetic fields.
Deep dive: physical mechanism
Optical pumping creates collective spin polarization, and optical rotation detects Larmor precession. Buffer gas and cell geometry control relaxation.
What is measured experimentally?
Read out rotation or resonance frequency as a field estimate.
Assumptions, noise and limitations
Spin-exchange, gradients and light shifts create bandwidth and accuracy tradeoffs.
Research and simulation exercise
Simulate damped spin precession and estimate B from noisy time traces.
Connect the ideas
Explore the chapter overview, learning path, and references.