Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 19: Transport: Topological Insulators 2 (jointly with TT, MA)

HL 19.2: Vortrag

Montag, 26. März 2012, 15:15–15:30, H 3005

Competition between d-wave and topological p-wave superconductivity in the doped Kitaev-Heisenberg model — •Timo Hyart¹, Anthony Wright¹, Giniyat Khaliullin², and Bernd Rosenow¹ — ¹Institut für Theoretische Physik, Universität Leipzig, D-04103, Leipzig, Germany — ²Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany

The competition between Kitaev and Heisenberg interactions away from half filling is studied for the hole-doped Kitaev-Heisenberg t-J_K-J_H model on a honeycomb lattice. While the isotropic Heisenberg coupling supports a time-reversal violating d-wave singlet state, we find that the Kitaev interaction favors a time-reversal invariant p-wave superconducting phase, which obeys the rotational symmetries of the microscopic model, and is robust for J_H<J_K/2. Within the p-wave superconducting phase, a critical chemical potential µ_c ≈ t separates a topologically trivial phase for |µ|< µ_c from a topologically non-trivial Z₂ time-reversal invariant spin-triplet phase for |µ|>µ_c.