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arXiv · 0706.1859

Failure of standard approximations of the exchange coupling in nanostructures

Jesper Pedersen·Christian Flindt·Niels Asger Mortensen·Antti-Pekka Jauho
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Abstract

We calculate the exchange coupling for a double dot system using a novel, numerically exact yet efficient technique, based on finite-element methods. Specifically, we evaluate the exchange coupling both for a quasi-one and a two-dimensional system, also including an applied magnetic field. Our numerical results provide a stringent test for standard approximation schemes (e.g., Heitler-London, Hund-Mulliken, Hubbard), and they show that the standard methods do not have reliable predictive power for real quantum-dot systems.

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Jesper Pedersen, Christian Flindt, Niels Asger Mortensen, Antti-Pekka Jauho. 2007-10-03. Failure of standard approximations of the exchange coupling in nanostructures. https://doi.org/10.1103/physrevb.76.125323

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