Enhanced Superconductivity in Restacked TaS Nanosheets.

Since interface superconductivity was discovered at the interface between two insulating layers LaAlO and SrTiO, such interface-induced superconducting systems have been a research hotspot in superconductivity. Here, we report homogeneous interfaces formed by stacking chemically exfoliated monolayer TaS nanosheets randomly. Enhanced superconductivity of T = 3 K is observed, compared with 0.8 K of parent 2H-TaS. The measurement of heat capacity shows the increase of electronic specific-heat coefficient γ of restacked TaS nanosheets compared to parent 2H-TaS crystals. Density functional theory calculations indicate that increase and delocalization of electron states near the Fermi surface due to the homogeneous interfaces effects could account for the enhanced superconductivity.