Spin-1/2 Kondo effect in an InAs nanowire quantum dot: the Unitary limit, conductance scaling and Zeeman splitting

TL;DR

This study investigates the spin-1/2 Kondo effect in an InAs nanowire quantum dot, demonstrating conductance scaling, reaching the Unitary limit, and revealing a strong magnetic field suppression possibly linked to spin-orbit coupling.

Contribution

It provides a comprehensive experimental analysis of the Kondo effect in InAs nanowire quantum dots, highlighting conductance scaling and unusual magnetic field suppression effects.

Findings

Kondo conductance reaches the Unitary limit in the nanowire quantum dot.

Conductance scales with temperature, magnetic field, and bias.

Magnetic field suppresses conductance more strongly than expected from g-factor.

Abstract

We report on a comprehensive study of spin-1/2 Kondo effect in a strongly-coupled quantum dot realized in a high-quality InAs nanowire. The nanowire quantum dot is relatively symmetrically coupled to its two leads, so the Kondo effect reaches the Unitary limit. The measured Kondo conductance demonstrates scaling with temperature, Zeeman magnetic field, and out-of-equilibrium bias. The suppression of the Kondo conductance with magnetic field is much stronger than would be expected based on a g-factor extracted from Zeeman splitting of the Kondo peak. This may be related to strong spin-orbit coupling in InAs.