Identifying the pairing symmetry in sodium cobalt oxide by Andreev edge states
arXiv:0901.4570 · doi:10.1103/PhysRevB.78.224522
Abstract
We study the Andreev edge states with different pairing symmetries and boundary topologies on semi-infinite triangular lattice of Na_xCoO_2.yH_2O. A general mapping from the two dimensional lattice to the one dimensional tight-binding model is developed. It is shown that the phase diagram of the Andreev edge states depends on the pairing symmetry and also the boundary topology. Surprisingly, the structure of the phase diagram crucially relies on the nodal points on the Fermi surface and can be explained by an elegant gauge argument. We compute the momentum-resolved local density of states near the edge and predict the hot spots which are measurable in Fourier-transformed scanning tunneling spectroscopy.
12 pages, 17 figures
References in corpus (7)
- Ferromagnetic fluctuation and possible triplet superconductivity in Na_xCoO_2*yH_2O: Fluctuation-exchange study of multi-orbital Hubbard model
- Spin singlet pairing in the superconducting state of NaxCoO2\cdot1.3H2O: evidence from a ^{59}Co Knight shift in a single crystal
- Symmetry of the superconducting order parameter in frustrated systems determined by the spatial anisotropy of spin correlations
- Na content dependence of superconductivity and the spin correlations in Na_{x}CoO_{2}\cdot 1.3H_{2}O
- Edge-currents in superconductors with a broken time-reversal symmetry
- Andreev Edge State on Semi-Infinite Triangular Lattice: Detecting the Pairing Symmetry in Na_0.35CoO_2.yH_2O
- Ground-State Degeneracy of Correlated Insulators with Edges