Thickness dependent interlayer transport in vertical MoS₂ Josephson junctions

Wereport on observations of thickness dependent Josephson coupling and multiple Andreev reflections (MAR) in vertically stacked molybdenum disulfide (MoS₂)-molybdenum rhenium (MoRe) Josephson junctions. MoRe, a chemically inert superconductor, allows for oxide free fabrication of high transparency vertical MoS₂ devices. Single and bilayer MoS₂ junctions display relatively large critical currents (up to 2.5 μA) and the appearance of sub-gap structure given by MAR. In three and four layer thick devices we observe orders of magnitude lower critical currents (sub-nA) and reduced quasiparticle gaps due to proximitized MoS₂ layers in contact with MoRe.Weanticipate that this device architecture could be easily extended to other 2D materials.