Superconductivity in NbX₂

NbX₂, X=S, Se, Te is a family of superconducting transition metal dichalcogenides. Recently, the advent of 2D materials brought new insights into the study of superconducting TMDCs, such as gate tunability and layer dependence study, revealing rich interplay of charge density waves, spin orbit coupling and superconductivity. ^[1][2] Ising superconductivity arises in few-layer NbSe₂ due to coexistence of SOC and superconductivity, showing strongly enhanced in-plane critical field ^[3] and 2nd order superconductor-insulator transition under in-plane magnetic field^[4]. In this work, we explored the cousins of NbSe₂ in the NbX₂ family: NbS₂ and NbTe₂, using transport measurements down to milliKelvin. We will show magnetoresistance measurement in normal and superconducting states, as well as angle dependence of critical field.

[1] Li, L. J., et al. Nature 529.7585 (2016): 185.
[2] Xi, Xiaoxiang, et al. Nat Nano 10.9 (2015): 765.
[3] Xi, Xiaoxiang, et al. Nat Phys 12.2 (2016): 139.
[4] Sohn, Egon, et al. Nat Mat 17.6 (2018): 504-508.