Volume 101, Number 4, February 2013
|Number of page(s)||6|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||05 March 2013|
Nano-pattern–induced ferromagnetism in strongly correlated electrons
1 Institut Néel, UPR2940, CNRS et Université de Grenoble - Grenoble, F-38042 France, EU
2 Jacobs University Bremen - Campus Ring 1, D-28759 Bremen, Germany, EU
Received: 19 September 2012
Accepted: 5 February 2013
Band ferromagnetism in strongly correlated electron systems is one of the most challenging issues in today's condensed-matter physics. In this theoretical work, we study the competition between kinetic term, Coulomb repulsion, and on-site correlated disorder for various lattice geometries. Unconventional and complex ferromagnetic phase diagrams are obtained: wide region of stability, cascade of transitions, re-entrance, high sensitivity to the carrier concentration and strongly inhomogeneous ground states for relatively weak on-site potential. The direct and systematic comparison with exact diagonalization shows that the unrestricted Hartree-Fock method is unexpectedly accurate for such systems, which allows large-size cluster calculations. A match of the order of 99.9% for weak and intermediate couplings is found, slightly reduced to about 95% in the large-repulsion regime. Nano-patterned lattices appear to be particularly promising candidates that could, with the tremendous progress in growing and self-organized techniques, be synthesized in the near future.
PACS: 75.10.Jm – Quantized spin models, including quantum spin frustration / 05.30.-d – Quantum statistical mechanics / 05.50.+q – Lattice theory and statistics (Ising, Potts, etc.)
© EPLA, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.