Competition between d-wave and topological p-wave superconductivity in the doped Kitaev-Heisenberg model

Date

Apr 23, 2012

Time

11:00 AM - 12:00 PM

Speaker

Prof. Dr. Bernd Rosenow

Affiliation

Institute for Theoretical Physics, University of Leipzig

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Grit Rötzer

Description

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_Hmu_c. While the symmetry of the superconducting order is equivalent to the B-phase of Helium-3 for symmetric exchange couplings and in the absence of a Zeeman field, we find different types of order in the presence of a Zeeman field and with asymmetric exchange couplings. Additional insights into the nature of the superconducting state are provided by the quasi-particle spectrum and the magnetic susceptibility of an isolated impurity, which we study? in the T-matrix approach.

Last modified: Apr 23, 2012, 9:35:11 AM