  Topological superconductors have drawn significant interest from the
scientific community due to the accompanying Majorana fermions. Here, we report
the discovery of electronic structure and superconductivity in high-entropy
ceramics Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2Cx (x = 1 and 0.8) combined with experiments
and first-principles calculations. The Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2Cx high-entropy
ceramics show bulk type-II superconductivity with Tc about 4.00 K (x = 1) and
2.65 K (x = 0.8), respectively. The specific heat jump is equal to 1.45 (x = 1)
and 1.52 (x = 0.8), close to the expected value of 1.43 for the BCS
superconductor in the weak coupling limit. The high-pressure resistance
measurements show that a robust superconductivity against high physical
pressure in Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2C, with a slight Tc variation of 0.3 K
within 82.5 GPa. Furthermore, the first-principles calculations indicate that
the Dirac-like point exists in the electronic band structures of
Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2C, which is potentially a topological superconductor.
The Dirac-like point is mainly contributed by the d orbitals of transition
metals M and the p orbitals of C. The high-entropy ceramics provide an
excellent platform for the fabrication of novel quantum devices, and our study
may spark significant future physics investigations in this intriguing
material.
