To study the interface between a conventional superconductor and a topological insulator, we fabricated Pb-Bi₂Te₃-Pb lateral and sandwiched junctions, and performed electron transport measurements down to low temperatures. The results show that there is a strong superconducting proximity effect between Bi₂Te₃ and Pb, as that a supercurrent can be established along the thickness direction of the Bi₂Te₃ flakes (100~300 nm thick) at a temperature very close to the superconducting T_c of Pb. Moreover, a Josephson current can be established over several microns in the lateral direction between two Pb electrodes on the Bi₂Te₃ surface. We have further demonstrated that superconducting quantum interference devices can be constructed based on the proximity-effect-induced superconductivity. The critical current of the devices exhibits s-wave-like interference and Fraunhofer diffraction patterns. With improved designs, Josephson devices of this type would provide a test-bed for exploring novel phenomena such as Majorana fermions in the future.

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