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arXiv · 1303.1968

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

Katalin Kamaras·Gyongyi Klupp·Peter Matus·Alexey Y. Ganin·Alec McLennan·Matthew J. Rosseinsky·Yasuhiro Takabayashi·Martin T. McDonald·Kosmas Prassides
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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.

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Katalin Kamaras, Gyongyi Klupp, Peter Matus, Alexey Y. Ganin, Alec McLennan, Matthew J. Rosseinsky, Yasuhiro Takabayashi, Martin T. McDonald, Kosmas Prassides. 2013-03-08. Mott localization in the correlated superconductor Cs3C60 resulting from the molecular Jahn-Teller effect. https://doi.org/10.1088/1742-6596/428/1/012002

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