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Magnetic Moment Formation in Quantum Point Contacts

P. S. Cornaglia·C. A. Balseiro·M. Avignon
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Abstract

We study the formation of local magnetic moments in quantum point contacts. Using a Hubbard-like model to describe point contacts formed in a two dimensional system, we calculate the magnetic moment using the unrestricted Hartree approximation. We analyze different type of potentials to define the point contact, for a simple square potential we calculate a phase diagram in the parameter space (Coulomb repulsion - gate voltage). We also present an analytical calculation of the susceptibility to give explicit conditions for the occurrence of a local moment, we present a simple scaling argument to analyze how the stability of the magnetic moment depends on the point contact dimensions.

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P. S. Cornaglia, C. A. Balseiro, M. Avignon. 2004-11-02. Magnetic Moment Formation in Quantum Point Contacts. https://doi.org/10.1103/physrevb.71.024432

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