Evidence for eight node mixed-symmetry superconductivity in a correlated organic metal
- Resource Type
- Working Paper
- Authors
- Guterding, Daniel; Diehl, Sandra; Altmeyer, Michaela; Methfessel, Torsten; Tutsch, Ulrich; Schubert, Harald; Lang, Michael; Müller, Jens; Huth, Michael; Jeschke, Harald O.; Valenti, Roser; Jourdan, Martin; Elmers, Hans-Joachim
- Source
- Phys. Rev. Lett. 116, 237001 (2016)
- Subject
- Condensed Matter - Superconductivity
Condensed Matter - Strongly Correlated Electrons
- Language
We report a combined theoretical and experimental investigation of the superconducting state in the quasi-two-dimensional organic superconductor $\kappa$-(ET)$_2$Cu[N(CN)$_2$]Br. Applying spin-fluctuation theory to a low-energy material-specific Hamiltonian derived from ab initio density functional theory we calculate the quasiparticle density of states in the superconducting state. We find a distinct three-peak structure that results from a strongly anisotropic mixed-symmetry superconducting gap with eight nodes and twofold rotational symmetry. This theoretical prediction is supported by low-temperature scanning tunneling spectroscopy on in situ cleaved single crystals of $\kappa$-(ET)$_2$Cu[N(CN)$_2$]Br with the tunneling direction parallel to the layered structure.
Comment: Accepted for publication in Phys. Rev. Lett.;6+12 pages;3+13 figures