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arXiv · 0710.1803

Kondo Universal Scaling for a Quantum Dot Coupled to Superconducting Leads

Christo Buizert·Akira Oiwa·Kenji Shibata·Kazuhiro Hirakawa·Seigo Tarucha
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Abstract

We study competition between the Kondo effect and superconductivity in a single self-assembled InAs quantum dot contacted with Al lateral electrodes. Due to Kondo enhancement of Andreev reflections the zero-bias anomaly develops sidepeaks, separated by the superconducting gap energy Delta. For ten valleys of different Kondo temperature T_K we tune the gap Delta with an external magnetic field. We find that the zero-bias conductance in each case collapses onto a single curve with Delta/kT_K as the only relevant energy scale, providing experimental evidence for universal scaling in this system.

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Christo Buizert, Akira Oiwa, Kenji Shibata, Kazuhiro Hirakawa, Seigo Tarucha. 2007-10-09. Kondo Universal Scaling for a Quantum Dot Coupled to Superconducting Leads. https://doi.org/10.1103/physrevlett.99.136806

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