Journal article ยท Preprint article
Failure of standard approximations of the exchange coupling in nanostructures
We calculate the exchange coupling for a double dot system using a numerically exact technique based on finite-element methods and an expansion in two-dimensional Gaussians. 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 of standard approximation schemes e.g., Heitler-London, Hund- Mulliken, Hubbard, and they show that the standard methods do not have reliable predictive power even for simple model systems. Their value in modeling more realistic quantum-dot structures is thus cast in serious doubt.
Language: | English |
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Publisher: | American Physical Society (APS) |
Year: | 2007 |
Pages: | 7 |
ISSN: | 1550235x , 10980121 and 01631829 |
Types: | Journal article and Preprint article |
DOI: | 10.1103/PhysRevB.76.125323 |
ORCIDs: | Mortensen, Asger and Jauho, Antti-Pekka |