# Spontaneous orbital-selective mott transitions and the Jahn-Teller metal of ${a}_{3}{\mathrm{c}}_{60}$

28.04.2017
Published in:
• Physical Review Letters. - 2017, vol. 118, no. 17, p. 177002
English The alkali-doped fullerides A3C60 are half-filled three-orbital Hubbard systems which exhibit an unconventional superconducting phase next to a Mott insulator. While the pairing is understood to arise from an effectively negative Hund coupling, the highly unusual Jahn-Teller metal near the Mott transition, featuring both localized and itinerant electrons, has not been understood. This property is consistently explained by a previously unrecognized phenomenon: the spontaneous transition of multiorbital systems with negative Hund coupling into an orbital-selective Mott state. This symmetry-broken state, which has no ordinary orbital moment, is characterized by an orbital-dependent two-body operator (the double occupancy) or an orbital-dependent kinetic energy and may be regarded as a diagonal-order version of odd-frequency superconductivity. We propose that the recently discovered Jahn-Teller metal phase of RbxCs3−xC60 is an experimental realization of this novel state of matter.
Faculty
Faculté des sciences et de médecine
Department
Département de Physique
Language
• English
Classification
Physics