Dimerization-induced enhancement of the spin gap in the quarter-filled two-leg rectangular ladder

Yan, Y and Mazumdar, S and Ramasesha, S (2006) Dimerization-induced enhancement of the spin gap in the quarter-filled two-leg rectangular ladder. In: Physical Review B, 73 (22). pp. 4418-4424.

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Abstract

We report density-matrix renormalization group calculations of spin gaps in the quarter-filled correlated two-leg rectangular ladder with bond-dimerization along the legs of the ladder. In the small rung-coupling region, dimerization along the leg bonds can lead to large enhancement of the spin gap. Electron-electron interactions further enhance the spin gap, which is nonzero for all values of the rung electron hopping and for arbitrarily small bond-dimerization. Very large spin gaps, as are found experimentally in quarter-filled band organic charge-transfer solids with coupled pairs of quasi one-dimensional stacks, however, occur within the model only for large dimerization and rung electron hopping that are nearly equal to the hopping along the legs. Coexistence of charge order and spin gap is also possible within the model for not too large intersite Coulomb interactions.

Item Type:	Journal Article
Publication:	Physical Review B
Publisher:	American Physical Society
Additional Information:	Copyright of this article belongs to American Physical Society.
Keywords:	spin systems;renormalisation;electron correlations;band structure;hopping conduction;spin Hamiltonians;exchange interactions(electron).
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	20 Mar 2009 06:19
Last Modified:	19 Sep 2010 04:55
URI:	http://eprints.iisc.ac.in/id/eprint/17074

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