Enhanced superconductivity upon weakening of charge density wave transport in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>2</mml:mn><mml:mi>H</mml:mi><mml:msub><mml:mtext>-TaS</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> 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 amplitude results in a substantial increase of the density of states at the Fermi energy, which can boost ${T}_{c}$ by an amount similar to that seen in experiment. Our results indicate competition between CDW order and superconductivity in ultrathin $2H\text{\ensuremath{-}}{\mathrm{TaS}}_{2}$ down to the monolayer limit, providing insight toward understanding correlated electronic phases in reduced dimensions.