2011/12/02 by D. Daghero, M. Tortello, Mauro Tortello +10 · 61 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Cooper pair #Electron #Electron pair #Fermion #Iron-based superconductors research #Isotropy #Pairing #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Rare-earth and actinide compounds #Spectroscopy #Superconductivity #Wave function #cond-mat.supr-con
paper · pdf · doi:10.1038/ncomms1785
published in Nature Communications 3(1), 786 (Nature Portfolio) · Main article with 4 figures, and supplementary info with 7 figures
arxiv created 2011/12/02 · openalex publication_date 2012/04/17 · arxiv updated 2015/06/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/08
Superconductivity is due to an attractive interaction between electrons that, below a critical temperature, drives them to form Cooper pairs and to condense into a ground state separated by an energy gap from the unpaired states. In the simplest cases, the pairing is mediated by lattice vibrations and the wavefunction of the pairs is isotropic. Less conventional pairing mechanisms can favour more exotic symmetries of the Cooper pairs. Here, we report on point-contact spectroscopy measurements in PuCoGa5, a moderate heavy-fermion superconductor with a record high critical temperature Tc=18.5 K. The results prove that the wavefunction of the paired electrons has a d-wave symmetry, with four lobes and nodes, and show that the pairing is likely to be mediated by spin fluctuations. Electronic structure calculations, which take into account the full structure of the f-orbital multiplets of Pu, provide a hint of the possible origin of these fluctuations. The heavy-fermion material PuCoGa5 is characterized by unconventional superconducting properties. By combining point-contact spectroscopy and first-principles calculations, this study reveals a d-wave symmetry in the system's order parameter.