Mott localization in the correlated superconductor Cs3C60 resulting from the molecular Jahn-Teller effect

Abstract

Cs3C60 is a correlated superconductor under pressure, but an insulator under ambient conditions. The mechanism causing this insulating behavior is the combination of Mott localization and the dynamic Jahn-Teller effect. We show evidence from infrared spectroscopy for the dynamic Jahn-Teller distortion. The continuous change with temperature of the splitting of infrared lines is typical Jahn-Teller behavior, reflecting the change in population of solid-state conformers. We conclude that the electronic and magnetic solid-state properties of the insulating state are controlled by molecular phenomena. We estimate the time scale of the dynamic Jahn-Teller effect to be above 10^(-11) s and the energy difference between the conformers less than 20 cm-1.

6 pages, 4 figures, 1 supplementary movie; XXI International Symposium on the Jahn-Teller Effect, Tsukuba, Japan, August 26-31, 2012

References in corpus (3)

• Modeling the Unconventional Superconducting Properties of Expanded A${}_3$C${}_{60}$ Fullerides
• NMR study of the Mott transitions to superconductivity in the two Cs_3C_60 phases
• Spin Dynamics at the Mott Transition and in the Metallic State of the Cs_{3}C_{60} Superconducting Phases

Cited by in corpus (7)

• Exotic s-wave superconductivity in alkali-doped fullerides
• Absence of Jahn-Teller transition in the hexagonal Ba3CuSb2O9 single crystal
• The role of electron-vibron interaction and local pairing in conductivity and superconductivity of alkali-doped fullerides
• Manifestation of vibronic dynamics in infrared spectra of Mott insulating fullerides
• Jahn-Teller effect in cubic fullerides A${}_3$C${}_{60}$
• Theoretical Phase diagram of unconventional alkali-doped fullerides
• Nanoscale orbital excitations and the infrared spectrum of a molecular Mott insulator: A15-Cs${}_3$C${}_{60}$