Experimental consequences of candidate pairings for superconducting topological insulators.

Genuine pairing symmetry of the superconducting topological insulators, including Cu$_{\mathrm{x}}$Bi$_{\mathrm{2}}$Se$_{\mathrm{3}}$, Bi$_{\mathrm{2}}$Se$_{\mathrm{3}}$, and Bi$_{\mathrm{2}}$Te$_{\mathrm{3}}$, are under debate. In this work, we make an extensive comparison on the experimental consequences of several candidate pairings. The physical quantities studied include the surface spectral functions, the surface local density of states, and the electronic thermal conductivities. Apparent differences in the results are found and can be used to identify the actual pairing symmetry. In particular, for model and parameters used in this work which are obtained by fitting first-principles calculations, we get interesting new results such as a segmental flat band of surface Andreev bound states for a spin-singlet pairing. A combination of several experimental techniques should be able to identify the genuine pairing symmetry.