Josephson coupling through one-dimensional ballistic channel in semiconductor-superconductor hybrid quantum point contacts

Abstract

We study a superconducting quantum point contact made of a narrow In${}_{0.75}$Ga${}_{0.25}$As channel with Nb proximity electrodes. The narrow channel is formed in a gate-fitted constriction of InGaAs/InAlAs/InP heterostructure hosting a two-dimensional electron gas. When the channel opening is varied with the gate, the Josephson critical current exhibits a discretized variation that arises from the quantization of the transverse momentum in the channel. The quantization of Josephson critical current persists down to the single-channel regime, providing an unambiguous demonstration of a semiconductor--superconductor hybrid Josephson junction involving only a single ballistic channel.

6 pages, 4 figures

References in corpus (7)

• Tunable Supercurrent Through Semiconductor Nanowires
• Quantum supercurrent transistors in carbon nanotubes
• Ge/Si nanowire mesoscopic Josephson junctions
• Exciting Andreev pairs in a superconducting atomic contact
• Andreev Level Qubit
• Collapse of thermal activation in moderately damped Josephson junctions
• Proximity effect in a two dimensional electron gas probed with a lateral quantum dot

Cited by in corpus (10)

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• Ballistic supercurrent discretization and micrometer-long Josephson coupling in germanium
• Quantifying quantum coherence of multiple-charge states in tunable Josephson junctions
• Spin triplet superconducting proximity effect in a ferromagnetic semiconductor
• Quantized critical supercurrent in SrTiO${}_3$-based quantum point contacts
• Proximity effect in a ferromagnetic semiconductor with spin-orbit interactions
• Gate-defined superconducting channel in magic-angle twisted bilayer graphene
• Investigation of InAs based devices for topological applications
• Andreev reflection and bound state formation in a ballistic two-dimensional electron gas probed by a quantum point contact