0000000001054792
AUTHOR
Shiang Fang
Enhanced superconductivity upon weakening of charge density wave transport in 2H-TaS2 in the two-dimensional limit
Layered transition-metal dichalcogenides that host coexisting charge-density wave (CDW) and superconducting orders provide ideal systems for exploring the effects of dimensionality on correlated electronic phases. Dimensionality has a profound effect on both superconductivity and CDW instabilities. Here we report a substantial enhancement of the superconducting ${T}_{c}$ to 3.4 K for $2H\text{\ensuremath{-}}{\mathrm{TaS}}_{2}$ in the monolayer limit, compared to 0.8 K in the bulk. In addition, the transport signature of a CDW phase transition vanishes in the two-dimensional limit. In our analysis of electronic and vibrational properties of this material, we show that a reduction of the CDW …
Enhanced Superconductivity and Suppression of Charge-density Wave Order in 2H-TaS$_2$ in the Two-dimensional Limit
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 t…