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RESEARCH PRODUCT
Enhanced Superconductivity and Suppression of Charge-density Wave Order in 2H-TaS$_2$ in the Two-dimensional Limit
Yafang YangShiang FangValla FatemiJonathan RuhmanEfr��n Navarro-moratallaKenji WatanabeTakashi TaniguchiEfthimios KaxirasPablo Jarillo-herrerosubject
Superconductivity (cond-mat.supr-con)Condensed Matter - Mesoscale and Nanoscale PhysicsCondensed Matter::SuperconductivityCondensed Matter - SuperconductivityMesoscale and Nanoscale Physics (cond-mat.mes-hall)FOS: Physical sciencesCondensed Matter::Strongly Correlated Electronsdescription
As superconductors are thinned down to the 2D limit, their critical temperature $T_c$ typically decreases. Here we report the opposite behavior, a substantial enhancement of $T_c$ with decreasing thickness, in 2D crystalline superconductor 2H-TaS$_2$. Remarkably, in the monolayer limit, $T_c$ increases to 3.4 K compared to 0.8 K in the bulk. Accompanying this trend in superconductivity, we observe suppression of the charge-density wave (CDW) transition with decreasing thickness. To explain these trends, we perform electronic structure calculations showing that a reduction of the CDW amplitude results in a substantial increase of the density of states at the Fermi energy, which contributes to the enhancement of $T_c$. Our results establish ultra-thin 2H-TaS$_2$ as an ideal platform to study the competition between CDW order and superconductivity.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-10-31 |