Protonation enhanced superconductivity in PdTe₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Electrochemical ionic liquid gating is a key technique for intercalating ions into layered materials, enabling property modulation.
• Palladium ditelluride (PdTe2) is a topological superconductor candidate whose properties are sensitive to external stimuli.

Purpose of the Study:

• To investigate the effect of electrochemical ionic liquid gating on the superconductivity of PdTe2.
• To explore methods for enhancing the superconducting properties of topological materials.

Main Methods:

• Electrochemical gating using an ionic liquid to induce protonation in PdTe2 single crystals.
• Measurement of superconducting transition temperature (SC Tc) and superconducting volume fraction.
• Post-gating storage of samples in a glove box to observe long-term effects.

Main Results:

• Superconducting transition temperature of PdTe2 was increased to approximately 3.2 K via room-temperature ionic gating and protonation.
• A further enhancement in both SC Tc and superconducting volume fraction was observed after 2 months of storage.
• Evidence suggests proton diffusion within the gated PdTe2 crystals, a rarely reported phenomenon in such experiments.

Conclusions:

• Electrochemical ionic liquid gating effectively enhances superconductivity in the topological superconductor candidate PdTe2.
• Proton diffusion may play a significant role in long-term property enhancement after gating, suggesting a common mechanism in electrochemical gating.
• The findings contribute to the understanding of superconducting mechanisms in PdTe2 and offer insights into electrochemical gating techniques.