Quantum electronic transport in (Bi_1-xSb_x)₂Se₃ topological insulator nanoribbon contacted with superconducting electrodes

The formation of spin-textured metallic edge states in topological insulators (TIs) enables highly coherent charge and spin transport. Combinations of TIs with conventional superconductors can also provide useful platforms for creating and manipulating emergent particles such as Majorana fermions, which are essential for topological quantum computers. Here, we report electronic transport properties of (Bi_1-xSb_x)₂Se₃ TI nanoribbon at low temperatures. With the magnetic field applied parallel to the nanoribbon axis, Aharonov-Bohm conductance oscillations were observed. In the superconducting state below the superconducting transition temperature of Al electrodes, the conductance enhancement due to Andreev reflection was observed.