An ever growing number of complex materials have been identified that defy the standard theory of metals. Among the simplest ways of generating an unconventional metal is through the two-channel Kondo effect, which leads to the formation of a fragile many-body state. This article reviews challenges, attemps and successes of realizing this two-channel Kondo effect in engineered structures and real quantum materials.

Two‐Channel Kondo Physics: From Engineered Structures to Quantum Materials Realizations