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Updated: Jul 12, 2026

11:52
Single Particle Cryo-Electron Microscopy: From Sample to Structure
Published on: May 29, 2021
Experiments on the structure of an individual elementary particle
Summary
Research on geonium, a man-made atom, measured the electron
Area of Science:
- Atomic Physics
- Quantum Electrodynamics
- Particle Physics
Background:
- Geonium, an artificial atom, has been studied since the 1970s.
- It is created from a single electron in specialized trapping fields at low temperatures.
- This research probes fundamental properties of the electron.
Purpose of the Study:
- To review research on geonium.
- To present precise measurements of the electron's gyromagnetic ratio (g).
- To investigate implications for electron structure and fundamental physics.
Main Methods:
- Creation of geonium in ultrahigh vacuum at liquid-helium temperature.
- Microwave spectroscopy experiments to measure the gyromagnetic ratio (g).
- Subtraction of quantum electrodynamics shifts for precise g-value determination.
Main Results:
- The electron gyromagnetic ratio g = 2.000000000110(60) was measured.
- A significant deviation (g - g(Dirac)) from the Dirac value suggests an electron radius.
- Extrapolation indicates an electron radius of approximately 10⁻²⁰ cm.
Conclusions:
- The measured g-value implies the electron possesses a spatial structure beyond the Dirac point model.
- This finding supports models extending particle structure to subquarks and a 'cosmon'.
- Speculative models link these concepts to the origin of the Big Bang.
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