Visualization by scanning SQUID microscopy of the intermediate state in the superconducting Dirac semimetal PdTe₂

The Dirac semimetal PdTe₂ becomes superconducting at a temperature T_c = 1.6 K. Thermodynamic and muon spin rotation experiments support type-I superconductivity, which is unusual for a binary compound. A key property of a type-I superconductor is the intermediate state, which presents a coexistence of superconducting and normal domains at magnetic fields lower than the thermodynamic critical field H_c. We present scanning SQUID microscopy studies of PdTe₂ revealing coexisting superconducting and normal domains of tubular and laminar shape as the magnetic field is more and more increased, thus confirming type-I superconductivity in PdTe2. Values for the domain wall width in the intermediate state have been derived. The field amplitudes measured at the surface indicate bending of the domain walls separating the normal and superconducting domains.