Surface superconductivity in a three-dimensional Cd3As2 semimetal
Abstract
We experimentally investigate charge transport through a single planar junction between Cd3As2 Dirac semimetal and a normal Au lead. For non-superconducting bulk Cd3As2 samples, we observe non-Ohmic dV/dI(V) curves, which strongly resemble standard Andreev reflection with well-defined superconducting gap. Andreev-like behavior is demonstrated for Cd3As2 samples with different surface and contact preparation techniques. We connect this behavior with surface superconductivity due to the flat-band formation in Cd3As2, which has been predicted theoretically. The conclusion on superconductivity is also supported by the gap suppression by magnetic fields or temperature.
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