Upper critical field reaches 90 tesla near the Mott transition in fulleride superconductors

作者：Kasahara Y^*; Takeuchi Y; Zadik R H; Takabayashi Y; Colman R H; McDonald R D; Rosseinsky M J; Prassides K; Iwasa Y^*

来源：Nature Communications, 2017, 8(1): 14467.

DOI：10.1038/ncomms14467

Controlled access to the border of the Mott insulating state by variation of control parameters offers exotic electronic states such as anomalous and possibly high-transition-temperature (T-c) superconductivity. The alkali-doped fullerides show a transition from a Mott insulator to a superconductor for the first time in three-dimensional materials, but the impact of dimensionality and electron correlation on superconducting properties has remained unclear. Here we show that, near the Mott insulating phase, the upper critical field H-c2 of the fulleride superconductors reaches values as high as similar to 90 T-the highest among cubic crystals. This is accompanied by a crossover from weak-to strong-coupling superconductivity and appears upon entering the metallic state with the dynamical Jahn-Teller effect as the Mott transition is approached. These results suggest that the cooperative interplay between molecular electronic structure and strong electron correlations plays a key role in realizing robust superconductivity with high-T-c and high-H-c2.

• 出版日期2017-2-17
• 单位Los Alamos; RIKEN