Two-band superconductivity with unconventional pairing symmetry in HfV2Ga4

Author(s)

Bhattacharyya, A. ^[1] ; Ferreira, R. P. ^[2] ; Santos, F. B. ^[3] ; Adroja, D. T. ^{[4, 5]} ; Lord, J. S. ^[4] ; Correa, L. E. ^[3] ; Machado, A. J. S. ^[3] ; Manesco, A. L. R. ^{[2, 6]} ; Eleno, L. T. F. ^[2]

Affiliation

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

^[2] Univ Scio Paulo EEL USP, Mat Engn Dept Demar, Computat Mat Sci Grp ComputEEL, Escola Engn Lorena, Lorena, SP - Brazil

^[3] Univ Scio Paulo EEL USP, Mat Engn Dept Demar, Escola Engn Lorena, Lorena, SP - Brazil

^[4] Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon - England

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

^[6] Delft Univ Technol, Kavli Inst Nanosci, Delft - Netherlands

• Document type: Journal article
• Source: PHYSICAL REVIEW RESEARCH; v. 2, n. 2 APR 1 2020.
• Web of Science Citations: 0

Abstract

In this Rapid Communication, we have examined the superconducting ground state of the HfV2Ga4 compound using resistivity, magnetization, zero-field (ZF), and transverse-field (TF) muon-spin relaxation and rotation (mu SR) measurements. Resistivity and magnetization unveil the onset of bulk superconductivity with T-C similar to 3.9 K. TF-mu SR measurements show the temperature dependence of the superfluid density, indicating, surprisingly, a nodal two-gap (s + d)-wave superconducting order parameter. In addition, the ZF muon relaxation rate increases with decreasing temperature below 4.6 K, suggesting the presence of weak spin fluctuations. These observations pointed to an unconventional multiband nature of the superconducting ground state. To better understand these findings, we carry out first-principles electronic-structure calculations, further highlighting multiple disconnected sheets with very different orbital weights and spin-orbit coupling composing the Fermi surface, bridging the way for a nodal multiband superconductivity scenario. In this vein, therefore, the HfV2Ga4 family stands out as an open avenue to novel unexplored unconventional superconducting compounds and an ideal playground to investigate the mechanisms behind such phenomena. (AU)

• FAPESP's process: 16/11565-7 - Investigation of the superconductivity and magnetism in compounds that crystallize on the YbMo2Al4 and IrIn3 prototype
• Grantee: Frederico Benedetto Santos
• Support type: Scholarships in Brazil - Doctorate (Direct)
• 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 type: Regular Research Grants
• FAPESP's process: 16/11774-5 - Study of superconductivity and magnetism in compounds which crystallize on the YbMo2Al4 and IrIn3 prototype structure
• Grantee: Antonio Jefferson da Silva Machado
• Support type: 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 type: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/10835-6 - Ab-initio investigation of electronic and phononic properties of superconducting TMDs
• Grantee: Pedro Pires Ferreira
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 19/07082-9 - Physics of graphene/superconductor junctions
• Grantee: Antonio Lucas Rigotti Manesco
• Support type: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 18/20546-1 - Single crystal growth of (Hf, Sc, RE)V2Ga4 (RE = rare earth) and (Fe, Co, Ru)1-xRMxGa3 (RM = refractory metals) compounds and the study of their Fermi surface, electronic structure, and superconducting properties under extreme conditions
• Grantee: Frederico Benedetto Santos
• Support type: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 16/10167-8 - Investigation of electronic and topological properties of superconductor-graphene heterojunctions for applications in quantum computation devices
• Grantee: Antonio Lucas Rigotti Manesco
• Support type: Scholarships in Brazil - Doctorate (Direct)