TY - JOUR
T1 - Dimerization-induced enhancement of the spin gap in the quarter-filled two-leg rectangular ladder
AU - Yan, Y.
AU - Mazumdar, S.
AU - Ramasesha, S.
PY - 2006
Y1 - 2006
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevB.73.224418
DO - 10.1103/PhysRevB.73.224418
M3 - Article
AN - SCOPUS:33745084925
SN - 0163-1829
VL - 73
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
IS - 22
M1 - 224418
ER -