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Kondo model for the "0.7 anomaly" in transport through a quantum point contact

Yigal Meir·Kenji Hirose·Ned S. Wingreen
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Abstract

Experiments on quantum point contacts have highlighted an anomalous conductance plateau at $0.7 (2e^2/h)$, with features suggestive of the Kondo effect. Here we present an Anderson model for transport through a point contact which we analyze in the Kondo limit. Hybridization to the band increases abruptly with energy but decreases with valence, so that the background conductance and the Kondo temperature $T_K$ are dominated by different valence transitions. This accounts for the high residual conductance above $T_K$. A spin-polarized current is predicted for Zeeman splitting $g^* μ_B B > k_B T_K,k_BT$.

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Yigal Meir, Kenji Hirose, Ned S. Wingreen. 2002-07-01. Kondo model for the "0.7 anomaly" in transport through a quantum point contact. https://doi.org/10.1103/physrevlett.89.196802

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