Achieving and tuning an unconventional superconducting state in PdTe2 grown by CVD

We are interested in investigating the superconducting properties of PdTe2 grown by Chemical Vapor Deposition (CVD). According to [1], PdTe2 has a three-fold rotational symmetry and is a candidate for topological superconductivity. PdTe2 thin films display a high critical in-plane field, more than 7 times that of the Pauli limit [2] revealing that it exhibits Type-II Ising superconductivity. Here, we investigate thin films of PdTe2 grown by using CVD. This synthesis process employs a bottom-up approach, allowing for the precise definition of material patterns through lithography. The synthesis begins with the deposition of 7nm of Pd onto (0001)-sapphire, followed by a tellurization process. Using a tube furnace, the source and substrate temperature were set to 500°C and 550°C, respectively, at 10-3 torr with Ar flow. The resulting material exhibits Raman peaks at 76.8 1/cm and 133.6 1/cm, which corresponds to phonon modes of PdTe2. The room temperature resistivity of the resulting material is 5.6×10-7Ω/cm. In low temperature transport measurements, we discern an onset of superconductivity at 2K. Our bottom-up growth process, calibrated in a Hall bar configuration, will be employed for the systematic investigation of the thermoelectric properties in the superconducting state of PdTe2.