  We study electronic properties of a superconducting topological insulator
whose parent material is a topological insulator. We calculate the temperature
dependence of the specific heat and spin susceptibility for four promising
superconducting pairings proposed by L. Fu and E. Berg (Phys. Rev. Lett. 105,
097001). Since the line shapes of temperature dependence of specific heat are
almost identical among three of the four pairings, it is difficult to identify
them simply from the specific heat. On the other hand, we obtain wide varieties
of the temperature dependence of spin susceptibility for each pairing
reflecting the spin structure of Cooper pair. We propose that the pairing
symmetry of superconducting topological insulator can be determined from
measurement of Knight shift by changing the direction of applied magnetic
field.
