  Majarona fermions (MFs) were predicted more than seven decades ago but are
yet to be identified [1]. Recently, much attention has been paid to search for
MFs in condensed matter systems [2-10]. One of the seaching schemes is to
create MF at the interface between an s-wave superconductor (SC) and a 3D
topological insulator (TI) [11-13]. Experimentally, progresses have been
achieved in the observations of a proximity-effect-induced supercurrent
[14-16], a perfect Andreev reflection [17] and a conductance peak at the Fermi
level [18]. However, further characterizations are still needed to clarify the
nature of the SC-TI interface. In this Letter, we report on a strong proximity
effect in Pb-Bi2Te3 hybrid structures, based on which Josephson junctions and
superconducting quantum interference devices (SQUIDs) can be constructed.
Josephson devices of this type would provide a test-bed for exploring novel
phenomena such as MFs in the future.
