  A topological superconductor (TSC) is characterized by the
topologically-protected gapless surface state that is essentially an Andreev
bound state consisting of Majorana fermions. While a TSC has not yet been
discovered, the doped topological insulator CuxBi2Se3, which superconducts
below ~3 K, has been predicted to possess a topological superconducting state.
We report that the point-contact spectra on the cleaved surface of
superconducting CuxBi2Se3 present a zero-bias conductance peak (ZBCP) which
signifies unconventional superconductivity. Theoretical considerations of all
possible superconducting states help us conclude that this ZBCP is due to
Majorana Fermions and gives evidence for a topological superconductivity in
CuxBi2Se3. In addition, we found an unusual pseudogap that develops below ~20 K
and coexists with the topological superconducting state.
