Hard superconducting gap in PbTe nanowires

Abstract

Semiconductor nanowires coupled to a superconductor provide a powerful testbed for quantum device physics such as Majorana zero modes and gate-tunable hybrid qubits. The performance of these quantum devices heavily relies on the quality of the induced superconducting gap. A hard gap, evident as vanishing subgap conductance in tunneling spectroscopy, is both necessary and desired. Previously, a hard gap has been achieved and extensively studied in III-V semiconductor nanowires (InAs and InSb). In this study, we present the observation of a hard superconducting gap in PbTe nanowires coupled to a superconductor Pb. The gap size ($\Delta$) is $\sim$ 1 meV (maximally 1.3 meV in one device). Additionally, subgap Andreev bound states can also be created and controlled through gate tuning. Tuning a device into the open regime can reveal Andreev enhancement of the subgap conductance, suggesting a remarkable transparent superconductor-semiconductor interface, with a transparency of $\sim$ 0.96. These results pave the way for diverse superconducting quantum devices based on PbTe nanowires.

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Cited by in corpus (9)

• Selective-Area-Grown PbTe-Pb Planar Josephson Junctions for Quantum Devices
• Gate-tunable subband degeneracy in semiconductor nanowires
• SQUID oscillations in PbTe nanowire networks
• Reducing disorder in PbTe nanowires for Majorana research
• Quantized Andreev conductance in semiconductor nanowires
• Anisotropy of PbTe nanowires with and without a superconductor
• Enhanced superconductivity in PbTe-In hybrids
• Presence versus absence of charging energies in PbTe quantum dots
• Spectroscopic Visualization of Hard Quasi-1D Superconductivity Induced in Nanowires Deposited on a Quasi-2D Indium film