Evidence for unconventional superconductivity and nontrivial topology in PdTe

Ramakanta Chapai; P V Sreenivasa Reddy; Lingyi Xing; David E Graf; Amar B Karki; Tay-Rong Chang; Rongying Jin

doi:10.1038/s41598-023-33237-5

Evidence for unconventional superconductivity and nontrivial topology in PdTe

Sci Rep. 2023 Apr 26;13(1):6824. doi: 10.1038/s41598-023-33237-5.

Authors

Ramakanta Chapai¹, P V Sreenivasa Reddy², Lingyi Xing¹, David E Graf³, Amar B Karki¹, Tay-Rong Chang^{2

4

5}, Rongying Jin^{6

7}

Affiliations

¹ Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA.
² Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan.
³ National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA.
⁴ Center for Quantum Frontiers of Research and Technology (QFort), Tainan, 70101, Taiwan.
⁵ Physics Division, National Center for Theoretical Sceinces, Taipei, 10617, Taiwan.
⁶ Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA. rjin@mailbox.sc.edu.
⁷ Center for Experimental Nanoscale Physics, Department of Physics and Astronomy, University of South Carolina, Columbia, SC, 29208, USA. rjin@mailbox.sc.edu.

Abstract

PdTe is a superconductor with T_c ~ 4.25 K. Recently, evidence for bulk-nodal and surface-nodeless gap features has been reported in PdTe. Here, we investigate the physical properties of PdTe in both the normal and superconducting states via specific heat and magnetic torque measurements and first-principles calculations. Below T_c, the electronic specific heat initially decreases in T³ behavior (1.5 K < T < T_c) then exponentially decays. Using the two-band model, the superconducting specific heat can be well described with two energy gaps: one is 0.372 meV and another 1.93 meV. The calculated bulk band structure consists of two electron bands (α and β) and two hole bands (γ and η) at the Fermi level. Experimental detection of the de Haas-van Alphen (dHvA) oscillations allows us to identify four frequencies (F_α = 65 T, F_β = 658 T, F_γ = 1154 T, and F_η = 1867 T for H // a), consistent with theoretical predictions. Nontrivial α and β bands are further identified via both calculations and the angle dependence of the dHvA oscillations. Our results suggest that PdTe is a candidate for unconventional superconductivity.

Abstract

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