Penetration depth study of the type-I superconductor PdTe₂

Superconductivity in the topological non-trivial Dirac semimetal PdTe₂ was recently shown to be type-I. We hereby report measurements of the relative magnetic penetration depth, Δλ, on several single crystals using a high precision tunnel diode oscillator technique. The temperature variation Δλ(T) follows an exponential function for T/T_c < 0.4, consistent with a fully-gapped superconducting state and weak or moderately coupling superconductivity. By fitting the data we extract a λ(0)-value of  ~500 nm. The normalized superfluid density is in good agreement with the computed curve for a type-I superconductor with nonlocal electrodynamics. Small steps are observed in Δλ(T), which possibly relates to a locally lower T_c due to defects in the single crystalline sample.