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Stark effect
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Spectral lines split in an electric field.
An electric field shifts and splits atomic energy levels; linear in E for hydrogen, quadratic otherwise.
Used in molecular spectroscopy.
Smaller than the Zeeman splitting for typical fields.
In more detail
The Stark effect splits atomic energy levels in an electric field, due to the interaction between the field and the atom's electric dipole moment. Hydrogen shows the effect clearly.
Real-world uses
- Stark effect measurements are used to determine atomic structure.
- Electric fields in plasmas are diagnosed using Stark broadening.
- Spectroscopists use the Stark effect to measure electric fields inside plasmas and gas discharges.
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Frequently asked questions
Is the Stark effect linear?
For hydrogen levels, it is linear for some states, and quadratic for others.
How is it different from Zeeman?
It uses electric fields instead of magnetic fields.
Is the Stark effect the same as Zeeman?
No. The Stark effect is caused by electric fields, while the Zeeman effect is caused by magnetic fields.
Related topics in Quantum Mechanics
Addition of angular momenta · Spin–orbit coupling · Zeeman effect · Perturbation theory · Variational principle · Dirac notation