Quantum transport of PbTe nanowires: a promising Majorana candidate

One-dimensional semiconductor nanowire proximitized by a superconductor forms a promising platform for topological qubits. Here, we report systematic transport characterizations of PbTe nanowires and explore its feasibility toward the realization of Majorana zero modes. In devices with a quantum point contact geometry (QPC), reproducible quantized conductance plateaus were observed for channel lengths up to 1.7 μm. The plateau values suggest that valley degeneracy has been lifted. For wires with a symmetric cross-sectional geometry, subband degeneracy can be observed and further lifted using a dual-gate design. In devices with a quantum dot (QD) geometry, we find that the charging energy scales with the cross-sectional area of the nanowire. As this area decreases, the charging energy increases from nearly undetectable (zero) to 210 ueV. These results on QPC and QD establish PbTe nanowires as a promising material candidate for future studies of topological superconductivity.