Kondo insulators

Kondo insulators are materials that act like insulators at low temperatures, meaning they don’t conduct electricity. They contain electrons that normally move freely but become strongly interacting with localized electrons in the material’s structure. This interaction causes the electrons to pair up and gaps to form in their energy levels, preventing electrical flow. Despite having metallic properties at higher temperatures, they transition to insulating behavior as they cool down, due to these many-body electronic effects. This unique behavior results from the complex interplay between localized and conduction electrons, making Kondo insulators interesting for studying quantum materials and potential electronic applications.