Electron-phonon superconductivity in C-doped topological nodal-line semimetal Zr5Pt3: a muon spin rotation and relaxation (mu SR) study

Author(s):Show less -

Bhattacharyya, A. ^[1] ; Ferreira, P. P. ^[2] ; Panda, K. ^[1] ; Masunaga, S. H. ^{[3, 4]} ; de Faria, L. R. ^[2] ; Correa, L. E. ^[2] ; Santos, F. B. ^[2] ; Adroja, D. T. ^{[5, 6]} ; Yokoyama, K. ^[6] ; Dorini, T. T. ^[7] ; Jardim, R. F. ^[3] ; Eleno, L. T. F. ^[2] ; Machado, A. J. S. ^[2]

Affiliation

^[1] Ramakrishna Mission Vivekananda Educ & Res Inst, Dept Phys, Howrah 711202, W Bengal - India

^[2] Univ Sao Paulo, Escola Engn Lorena, DEMAR, Lorena - Brazil

^[3] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo, SP - Brazil

^[4] Ctr Univ, FEI, Dept Fis, Sao Bernardo Do Campo - Brazil

^[5] Univ Johannesburg, Phys Dept, Highly Correlated Matter Res Grp, ZA-2006 Auckland Pk - South Africa

^[6] Rutherford Appleton Lab, ISIS Facil, Didcot OX11 OQX, Oxon - England

^[7] Univ Lorraine, CNRS, IJL, Nancy - France

• Document type: Journal article
• Source: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 34, n. 3 JAN 19 2022.
• Web of Science Citations: 0

Abstract

In the present work, we demonstrate that C-doped Zr5Pt3 is an electron-phonon superconductor (with critical temperature T (C) = 3.8 K) with a nonsymmorphic topological Dirac nodal-line semimetal state, which we report here for the first time. The superconducting properties of Zr5Pt3C0.5 have been investigated by means of magnetization, resistivity, specific heat, and muon spin rotation and relaxation (mu SR) measurements. We find that at low temperatures, the depolarization rate is almost constant and it can be well described by a single-band s-wave model with a superconducting gap of 2 Delta(0)/k (B) T (C) = 3.84, somewhat higher than the value of BCS theory. From the transverse field mu SR analysis, we estimate the London penetration depth lambda (L) = 469 nm, superconducting carrier density n (s) = 1.83 x 10(26) m(-3), and effective mass m{*} = 1.428m (e). The zero field mu SR confirms the absence of any spontaneous magnetic field in the superconducting ground state. In order to gain additional insights into the electronic ground state of C-doped Zr5Pt3, we also performed first-principles calculations within the framework of density functional theory (DFT). The observed homogenous electronic character of the Fermi surface as well as the mutual decrease of T (C) and density of states at the Fermi level are consistent with the experimental findings of this study. However, the band structure reveals the presence of robust, gapless fourfold-degenerate nodal lines protected by 6(3) screw rotations and glide mirror planes. Therefore, Zr5Pt3 represents a novel, unprecedented condensed matter system to investigate the intricate interplay between superconductivity and topology. (AU)

• FAPESP's process: 19/14359-7 - Growth single crystals and investigation of superconducting topological properties in metal transition dichalcogenides
• Grantee: Antonio Jefferson da Silva Machado
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/05005-7 - Computational Materials Laboratory for the ab initio study of the stability of intermetallic compounds
• Grantee: Luiz Tadeu Fernandes Eleno
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/08819-2 - Growth of single crystals of CdI2 prototype dicalcogens and investigation of superconducting properties
• Grantee: Lucas Eduardo Corrêa
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 20/08258-0 - Ab initio study of superconducting and topological systems
• Grantee: Pedro Nunes Ferreira
• Support Opportunities: Scholarships in Brazil - Doctorate