Enhanced Superconductivity in 2H-TaS Devices through in Situ Molecular Intercalation.

The intercalation of guest species into the gap of van der Waals materials often leads to the emergence of intriguing phenomena such as superconductivity. While intercalation-induced superconductivity has been reported in several bulk crystals, reaching a zero-resistance state in flakes remains challenging. Here, we show a simple method for enhancing the superconducting transition in tens-of-nanometers thick 2H-TaS crystals contacted by gold electrodes through in situ intercalation. Our approach enables measuring the electrical characteristics of the same flake before and after intercalation, permitting us to precisely identify the effect of the guest species on the TaS transport properties. We find that the intercalation of amylamine molecules into TaS flakes causes a suppression of the charge density wave and an increase in the superconducting transition with an onset temperature above 3 K. Additionally, we show that a fully developed zero-resistance state can be achieved in flakes by engineering the conditions of the chemical intercalation. Our findings pave the way for the integration of chemically tailored intercalation compounds in scalable quantum technologies.