# Evidence for multi-valley superconductivity and possible charge-density waves in ion-gated transition metal dichalcogenide $MoS_2$.

Piatti E., De Fazio D., Daghero D., Tortello M., Romanin D., Ye J. T., Ferrari A. C., Gonnelli R. S.

Relazione su invito
II - Fisica della materia
GSSI Ex ISEF - Aula C - Mercoledì 25 h 16:30 - 19:00
Low-temperature electric-transport measurements in field-effect--doped and ion-intercalated $MoS_2$ show that: i) superconductivity (sc) appears only when the Fermi level crosses the second high-energy spin-orbit-coupling split sub-band at $Q$ in the FBZ, while the maximum $T_c$ occurs when this sub-band is highly populated; ii) the resistivity of ultra-highly-doped $Li_{x}MoS_{2}$ flakes is anomalous, suggesting the presence of charge-density waves that could lead to the disappearance of sc. These results, accompanied by detailed DFT calculations of the electronic properties, highlight for the first time the crucial role of the Lifshitz transitions associated to the doping in the induction and optimization of $MoS_2$ superconductivity.