Penetration depth study of the type-I superconductor PdTe₂

Area of Science:

• Condensed matter physics
• Materials science
• Topological materials

Background:

• Topological non-trivial Dirac semimetal PdTe2 exhibits type-I superconductivity.
• Understanding the superconducting properties of topological materials is crucial for novel electronic applications.

Purpose of the Study:

• To measure the relative magnetic penetration depth of PdTe2 single crystals.
• To characterize the superconducting gap and coupling strength.
• To verify the type-I superconductivity and nonlocal electrodynamics.

Main Methods:

• High precision tunnel diode oscillator technique.
• Measurement of temperature variation of magnetic penetration depth.
• Data fitting to extract superconducting parameters.

Main Results:

• The temperature dependence of magnetic penetration depth follows an exponential function, indicating a fully-gapped superconducting state.
• Weak or moderately coupling superconductivity was observed.
• A magnetic penetration depth (λ) of approximately 500 nm was determined.
• Normalized superfluid density aligns with theoretical predictions for type-I superconductors with nonlocal electrodynamics.
• Minor steps in magnetic penetration depth suggest localized defects.

Conclusions:

• The study confirms type-I superconductivity in PdTe2.
• PdTe2 exhibits a fully-gapped superconducting state with weak or moderate electron-phonon coupling.
• Observed magnetic penetration depth and superfluid density are consistent with theoretical models.
• Sample defects may influence local superconducting properties.