Evidence of Incoherent Carriers Associated with Resonant Impurity Levels and Their Influence on Superconductivity in the Anomalous Superconductor Pb 1 − x Tl x Te

P. Giraldo-Gallo (1, 2, 3) , P. Walmsley (1) , B. Sangiorgio (4) , S. c. Riggs (2) , R. d. Mcdonald (5) , L. Buchauer (6) , B. Fauqué (6) , Chang Liu (7) , N. a. Spaldin (8) , K. Behnia (9, 10, 6) , I. r. Fisher (1)

1 Stanford University
2 NHMFL - National High Magnetic Field Laboratory
3 UNIANDES - Universidad de los Andes [Bogota]
4 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
5 LANL - Los Alamos National Laboratory
6 ESPCI Paris - Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris
7 ISU - Iowa State University
8 ETH - Etude multi-échelle des Transferts en milieux Hétérogènes
9 LSLP - Laboratoire de Spectroscopie en Lumière Polarisée
10 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)

We present a combined experimental and the oretical study of the evolution of the Fermi surface of the anomalous superconductor Pb1−x TlxTe as a function of thallium concentration, drawing on a combination of magneto transport measurements Shubnikov de Haas oscillations and Hall coefficient), Angle Resolved Photoemission Spectroscopy (ARPES), and density functional theory (DFT) calculations of the electronic structure. Our results indicate that for Tl concentrations beyond a critical value the Fermi energy coincides with resonant impurity states in Pb1−x TlxTe, and we rule out the presence of an additional valence band maximum at the Fermi energy. Comparison tonon-superconducting Pb1−x NaxTe implies that the presence of these impurity states at the Fermienergy provides the enhanced pairing interaction and thus also the anomalously high temperatures uper conductivity in this material.

Domaines: Physique [physics]; Matière Condensée [cond-mat]; Supraconductivité [cond-mat.supr-con]

P. Giraldo-Gallo, P. Walmsley, B. Sangiorgio, S. c. Riggs, R. d. Mcdonald, et al.. Evidence of Incoherent Carriers Associated with Resonant Impurity Levels and Their Influence on Superconductivity in the Anomalous Superconductor Pb 1 − x Tl x Te. Physical Review Letters, 2018, 121 (20), ⟨10.1103/PhysRevLett.121.207001⟩. ⟨hal-02382700⟩