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Zeeman effect
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Spectral lines split in a magnetic field.
An external magnetic field splits atomic levels by ΔE = m_j g_J μ_B B, making spectral lines split into several components.
Used to measure magnetic fields on the Sun.
Anomalous Zeeman effect involves spin.
In more detail
The Zeeman effect splits atomic energy levels in a magnetic field, because magnetic moments interact with the field. The splitting is proportional to the field strength.
Real-world uses
- Astronomers measure magnetic fields in stars and sunspots using the Zeeman effect.
- MRI relies on spin splitting in magnetic fields.
- Astronomers and physicists use the Zeeman effect to measure magnetic fields in stars and sunspots from spectral line splitting.
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Frequently asked questions
Why do spectral lines split?
Because the magnetic field separates energy levels with different orientations.
Is it always proportional to B?
For weak fields, yes. For strong fields, the splitting changes form.
Why do lines split in a magnetic field?
The magnetic field shifts the energy of each state depending on its magnetic quantum number, splitting the line.
Related topics in Quantum Mechanics
Angular momentum in QM · Addition of angular momenta · Spin–orbit coupling · Stark effect · Perturbation theory · Variational principle