Editing Zeeman effect (section)

==Applications==

===Astrophysics===
[[File:Sunzeeman1919.png|thumb|right|200px|Zeeman effect on a sunspot spectral line]]
[[George Ellery Hale]] was the first to notice the Zeeman effect in the solar spectra, indicating the existence of strong magnetic fields in sunspots. Such fields can be quite high, on the order of 0.1 [[Tesla (unit)|tesla]] or higher.  Today, the Zeeman effect is used to produce [[Solar magnetogram|magnetogram]]s showing the variation of magnetic field on the Sun,<ref>{{Cite journal |last=Schad |first=Thomas A. |last2=Petrie |first2=Gordon J.D. |last3=Kuhn |first3=Jeffrey R. |last4=Fehlmann |first4=Andre |last5=Rimmele |first5=Thomas |last6=Tritschler |first6=Alexandra |last7=Woeger |first7=Friedrich |last8=Scholl |first8=Isabelle |last9=Williams |first9=Rebecca |last10=Harrington |first10=David |last11=Paraschiv |first11=Alin R. |last12=Szente |first12=Judit |date=2024-09-13 |title=Mapping the Sun’s coronal magnetic field using the Zeeman effect |url=https://www.science.org/doi/10.1126/sciadv.adq1604 |journal=Science Advances |language=en |volume=10 |issue=37 |doi=10.1126/sciadv.adq1604 |issn=2375-2548 |pmc=11421591 |pmid=39259791}}</ref> and to analyze the magnetic field geometries in other stars.<ref>{{Cite journal |last=Kochukhov |first=Oleg |date=December 2021 |title=Magnetic fields of M dwarfs |journal=The Astronomy and Astrophysics Review |volume=29 |issue=1 |pages=1 |doi=10.1007/s00159-020-00130-3 |arxiv=2011.01781 |issn=0935-4956}}</ref>

===Laser cooling===
The Zeeman effect is utilized in many [[laser cooling]] applications such as a [[magneto-optical trap]] and the [[Zeeman slower]].<ref>{{Cite journal |last=Bowden |first=William |last2=Gunton |first2=Will |last3=Semczuk |first3=Mariusz |last4=Dare |first4=Kahan |last5=Madison |first5=Kirk W. |date=2016-04-18 |title=An adaptable dual species effusive source and Zeeman slower design demonstrated with Rb and Li |url=https://pubs.aip.org/aip/rsi/article-abstract/87/4/043111/361124/An-adaptable-dual-species-effusive-source-and?redirectedFrom=fulltext |journal=Review of Scientific Instruments |volume=87 |issue=4 |pages=043111 |doi=10.1063/1.4945567 |issn=0034-6748|arxiv=1509.07460 }}</ref>

===Spintronics===
Zeeman-energy mediated coupling of spin and orbital motions
is used in [[spintronics]] for controlling electron spins in quantum dots through [[electric dipole spin resonance]].<ref>Y. Tokura, W. G. van der Wiel, T. Obata, and S. Tarucha, Coherent single electron spin control in a slanting Zeeman field, Phys. Rev. Lett. '''96''', 047202 (2006)</ref>

===Metrology===
Old high-precision frequency standards, i.e. hyperfine structure transition-based atomic clocks, may require periodic fine-tuning due to exposure to magnetic fields. This is carried out by measuring the Zeeman effect on specific hyperfine structure transition levels of the source element (cesium) and applying a uniformly precise, low-strength magnetic field to said source, in a process known as [[degaussing]].<ref>{{cite AV media |people=Verdiell, Marc (CuriousMarc) |date=October 31, 2022 |title=How an Atomic Clock Really Works, Round 2: Zeeman Alignment |type=YouTube video |language=English |url=https://www.youtube.com/watch?v=xTy1kY_wtsY |access-date=March 11, 2023}}</ref>

The Zeeman effect may also be utilized to improve accuracy in [[atomic absorption spectroscopy]].{{Citation needed|date=March 2024}}

===Biology===
A theory about the [[magnetic sense]] of birds assumes that a protein in the retina is changed due to the Zeeman effect.<ref>{{cite journal |last1=Thalau |first1=Peter |last2=Ritz |first2=Thorsten |last3=Burda |first3=Hynek |last4=Wegner |first4=Regina E. |last5=Wiltschko |first5=Roswitha |title=The magnetic compass mechanisms of birds and rodents are based on different physical principles |journal= Journal of the Royal Society Interface|date=18 April 2006 |volume=3 |issue=9 |pages=583–587 |pmc=1664646 |doi=10.1098/rsif.2006.0130 |pmid=16849254 }}</ref>

===Nuclear spectroscopy===
The nuclear Zeeman effect is important in such applications as [[nuclear magnetic resonance]] spectroscopy, [[magnetic resonance imaging]] (MRI), and [[Mössbauer spectroscopy]].{{Citation needed|date=April 2024}}

===Other===
The [[electron spin resonance]] spectroscopy is based on the Zeeman effect.{{Citation needed|date=April 2024}}