DOE Science Showcase - Kondo Effect
to excite electrons inside the sample. The X-ray loses
energy during the process and then is scattered out
of the sample. A fine analysis of the scattered X-rays
yields insight into the mechanism that controls
the strength of the Kondo Effect.
Courtesy Brookhaven National Laboratory
For more than 50 years, scientists around the world have attempted to understand the intriguing phenomena of the Kondo effect. Most materials that conduct electric current offer less resistance to the current flow as they get colder. However, when magnetic impurity atoms are added to non-magnetic conductors, their resistance increases below a certain temperature. Japanese theorist Jun Kondo first worked out a mathematical model of how this effect results from the way the magnetic atoms interact with the current. Today the effect is named after him.
While experiments show that the resistance of these materials is still finite at low temperatures, Kondo's mathematical model implies that the resistance would be infinite at absolute zero. Later, American theoretical physicist Kenneth Wilson developed a mathematical technique for analyzing processes like the Kondo effect, which are significantly influenced by interactions of many sizes instead of being dominated by a single interaction at one scale. Applying his method to materials that exhibit the Kondo effect, Wilson showed how their resistance remains finite no matter how cold they get.
Dilute magnetic alloys and their unusual behaviors are important tools for scientific research in topics such as ferromagnetism, superconductivity, and other solid-state phenomena. The Kondo effect provides insight to the electronic properties of a wide variety of materials and opens doors to new discoveries.
Related Research Information in DOE Databases
- DOE PAGESBeta – journal articles and accepted manuscripts related to the Kondo Effect resulting from DOE funding.
- SciTech Connect – Kondo Effect research from DOE science, technology, and engineering programs.
- In the OSTI Collections – The Kondo Effect, Dr. William Watson
For additional information, see the OSTI Catalogue of Collections.
Additional Resources
- Kondo effect, Wikipedia
- Kondo effect, Scholarpedia
- Revival of the Kondo effect, arXiv.org
- Professor Jun Kondo, National Institute of Advanced Industrial Science and Technology
- Resistance Minimum in Dilute Magnetic Alloys, Jun Kondo
- Unlocking the secret of the Kondo effect, EurekAlert!
- The ferromagnetic Kondo effect, Phys.org
- Kenneth Wilson and Renormalization, DOE R&D Accomplishments
- The Remarkable Legacy of Kenneth Geddes Wilson, OSTIblog
- Self-contained Kondo effect in single molecules, SciTech Connect
- Physicists Solve Low-Temperature Magnetic Mystery, Brookhaven National Laboratory (see related image)
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