Phenomenological model for the 0.7 conductance feature in quantum wires

Abstract

One dimensional (1D) quantum wires exhibit a conductance feature near 0.7 x 2e^2/h in connection with many-body interactions involving the electron spin. With the possibility of exploiting this effect for novel spintronic device applications, efforts have focused on uncovering a complete microscopic theory to explain this conductance anomaly. Here we present conductance calculations based on a simple phenomenological model for a gate-dependent spin gap that are in excellent agreement with experimental data taken on ultra-low-disorder quantum wires. Taken together the phenomenology and experimental data indicate that the 0.7 feature depends strongly on the potential profile of the contact region, where the reservoirs meet the 1D wire. Microscopic explanations that may under-pin the phenomenological description are also discussed.

Heavily revised version, including new figures. Low Res Figures with arxiv version. Email for better quality figs. Any comments on the work are always welcome. email: [email protected]

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Cited by in corpus (39)

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• The influence of device geometry on many-body effects in quantum point contacts: Signatures of the 0.7 anomaly, exchange and Kondo
• Ferromagnetic Spin Coupling as the Origin of 0.7 Anomaly in Quantum Point Contacts
• Statistical study of conductance properties in one-dimensional quantum wires focussing on the 0.7 anomaly
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• Length-Dependent Conductance of a Spin-Incoherent Hubbard chain; Monte Carlo Calculations
• Suppression of Shot Noise in Quantum Point Contacts in the "0.7" Regime
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• Tunable Charge Detectors for Semiconductor Quantum Circuits
• Temperature Dependence of Spin-Split Peaks in Transverse Electron Focusing
• Direct observation of non-equilibrium spin population in quasi-one-dimensional nanostructures
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• A Scaling Approach for Interacting Quantum Wires -a Possible Explanation for the 0.7 Anomalous Conductance
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• Influence of Impurity Scattering on the Conductance Anomalies of Quantum Point Contacts with Lateral Spin-Orbit Coupling
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