Quasi-Kondo phenomenon due to the dynamical Jahn-teller effect

Hotta, Takashi

Physical Review Letters, 96(19), p.197201_1 - 197201_4, 2006/05

https://doi.org/10.1103/PhysRevLett.96.197201

A mechanism of non-magnetic Kondo effect is proposed on the basis of a multiorbital Anderson model coupled with dynamical Jahn-Teller (JT) phonons. An electron system coupled dynamically with JT phonons has a vibronic ground state with double degeneracy due to clockwise and anti-clockwise rotational modes with entropy of . When a temperature is lower than a characteristic energy to turn the rotational direction, the rotational degree of freedom is eventually suppressed and the corresponding entropy is released, leading to quasi-Kondo behavior. We discuss possible relevance of this quasi-Kondo phenomenon to electronic properties of filled skutterudites.