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arXiv · 1404.5390

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

Hiroshi Irie·Yuichi Harada·Hiroki Sugiyama·Tatsushi Akazaki
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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.

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Hiroshi Irie, Yuichi Harada, Hiroki Sugiyama, Tatsushi Akazaki. 2014-04-22. Josephson coupling through one-dimensional ballistic channel in semiconductor-superconductor hybrid quantum point contacts. https://doi.org/10.1103/physrevb.89.165415

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