Research: New insights into the Kondo physics via an exactly solvable model

The Kondo problem concerns the interplay between a localized magnetic impurity and itinerant electrons and has been a central subject of condensed matter physics since its inception. The attempt to solve the Kondo problem has stimulated the development of numerous theoretical and numerical techniques for quantum many-body systems, such as Wilson’s numerical renormalization group.

Despite the existence of huge literature on the Kondo problem, we have brought new insights into the Kondo physics by constructing an exactly solvable model. The ground-state wave function of this model is highly structured and can be constructed using a conformal field theory, which is known to describe the low-energy physics of the spin-1/2 Kondo problem. This established link opens up the exciting possibility of understanding more complicated Kondo problems via trial wave functions and exactly solvable models.

H.-H. Tu and Y.-H. Wu
Exactly Solvable Quantum Impurity Model with Inverse-Square Interactions,
Phys. Rev. Lett. 123, 066406 (2019)