Spin Depolarization in Quantum Wires Polarized Spontaneously in a Zero Magnetic Field

Abstract

The conditions for a spontaneous spin polarization in a quantum wire positioned in a zero magnetic field are analyzed under weak population of one-dimensional subbands that gives rise to the efficient quenching of the kinetic energy by the exchange energy of carriers. The critical linear concentration of carriers above which the quasi one-dimensional gas undergoes a complete spin depolarization is determined by the Hartree-Fock approximation. The dependence of the critical linear concentration on the concentration of carriers is defined to reveal the interplay of the spin depolarization with the evolution of the 0.7 (2e2/h) feature in the quantum conductance staircase from the e2/h to 3/2 (e2/h) values. This dependence is used to study the effect of the hole concentration on the 0.7 (2e2/h) feature in the quantum conductance staircase of the quantum wire prepared inside the p-type silicon quantum well using the split-gate technique. The 1D channel is demonstrated to be spin-polarized at the linear concentration of holes lower than the critical linear concentration, because the 0.7 (2e2/h) feature is close to the value of 0.5 (2e2/h) that indicates the spin degeneracy lifting for the first step of the quantum conductance staircase. The 0.7 (2e2/h) feature is found to take however its normal magnitude when the linear concentration of holes attains the critical value corresponding to the spin depolarization. The variations in the height of the 0.7 (2e2/h) feature observed in the hole quantum conductance staircase that is revealed by the p-type silicon quantum wire seem to be related to the evidences of the quantum conductance staircase obtained by varying the concentration of electrons in the 1D channel prepared inside the GaAs-AlGaAs heterojunction.

27 pages, 5 figures

References in corpus (13)

• Possible Spin Polarization in a One-Dimensional Electron Gas
• The Low-Temperature Fate of the 0.7 Structure in a Point Contact: A Kondo-like Correlated State in an Open System
• Interaction Effects in a One-Dimensional Constriction
• Kondo model for the "0.7 anomaly" in transport through a quantum point contact
• The low-density spin susceptibility and effective mass of mobile electrons in Si inversion layers
• Spin Properties of Low Density One-Dimensional Wires
• Hole-Hole Interaction Effect in the Conductance of the Two-Dimensional Hole Gas in the Ballistic Regime
• Ferromagnetic correlations in quasi-one-dimensional conducting channels
• Interaction corrections to the Hall coefficient at intermediate temperatures
• Observation of the Metal-Insulator Transition in Two-Dimensional n-type GaAs
• Josephson Junctions with Minimal Length
• Realistic Electron-Electron Interaction in a Quantum Wire
• Spontaneous Magnetisation in a Quantum Wire

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