Angle-resolved photoemission spectroscopy (ARPES) experiments on PdTe, a 3D-Dirac semimetal and a superconductor below ∼ 4.3 K, have revealed compelling evidences of the presence of bulk nodes in the superconducting order parameter [1]. We investigated the magnetic field dependence of the specific heat down to temperatures ∼58 mK. We observed that the low-temperature specific heat in externally applied magnetic field exhibits a power-law field dependence, a characteristic of unconventional superconductivity. The zero-field low-temperature electronic specific heat follows a cubic temperature dependence, which is a signature of the presence of bulk point nodes [2]. The magnetic-field-dependent Andreev reflection spectroscopy results support the nodeless surface and nodal bulk orders, and the nodal bulk gap facilitates early vortex entry, which in turn disrupts the fragile surface superconductivity. These intriguing observations suggest that PdTe is a fascinating topological material that exhibits both Dirac semimetallic properties and superconductivity with point nodal gap symmetry.

References:

1. X. P. Yang, Y. Zhong, S. Mardanya, T. A. Cochran, R. Chapai, A. Mine, J. Zhang, J. Sánchez-Barriga, Z.-J. Cheng, O.J. Clark et al., Coexistence of bulk-nodal and surface-nodeless Cooper pairings in a superconducting Dirac semimetal, Phys. Rev. Lett. 130, 046402 (2023).

2. C. S. Yadav , Sudeep Kumar Ghosh , Pankaj Kumar , A. Thamizhavel , and P. L. Paulose, Signature of point nodal superconductivity in the Dirac semimetal PdTe, Phys. Rev. B 110, 054515 (2024)

3. A. Mishra, G. Mohmad, K. Bansal, Mohd. Monish, Pankaj Kumar, C. S. Yadav, Goutam Sheet; Magnetic field decouples nodeless surface and nodal bulk orders in PdTe, arXiv:2601.07493v2