2004/11/02 by Pablo S. Cornaglia, P. S. Cornaglia, C. A. Balseiro +1 · 1 citation
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.024432
published as Phys. Rev. B 71, 024432 (2005) · 7 pages, 2 figures
arxiv created 2004/11/02 · openalex publication_date 2005/01/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.