TY - JOUR
T1 - Competition between spin exchange and correlated hopping
AU - Saiga, Y.
AU - Imada, M.
N1 - Funding Information:
One of the authors (Y.S.) is grateful to M. Oshikawa, K. Okamoto and M. Kohno for valuable discussions. Y.S. is supported by JSPS Research Fellowships for Young Scientists.
PY - 2002
Y1 - 2002
N2 - The ground-state phase diagram is numerically studied for an electronic model consisting of the spin exchange term (J) and the correlated hopping term (t3: the three-site term). This model has no single-particle hopping and the ratio of the two terms is controlled by a parameter α≡4t3/J. The case of α=1 corresponds to complete suppression of single-particle hopping in the strong-coupling limit of the Hubbard model. In one dimension, phase separation takes place below a critical value αc = 0.36-0.63 which depends on the electron density. Spin gap opens in the whole region except the phase-separated one. For α ≳ 1.2 and low hole densities, charge-density-wave correlations are the most dominant, whereas singlet-pairing correlations are the most dominant in the remaining region. The possibility of superconductivity in the two-dimensional case is also discussed, based on equal-time pairing correlations.
AB - The ground-state phase diagram is numerically studied for an electronic model consisting of the spin exchange term (J) and the correlated hopping term (t3: the three-site term). This model has no single-particle hopping and the ratio of the two terms is controlled by a parameter α≡4t3/J. The case of α=1 corresponds to complete suppression of single-particle hopping in the strong-coupling limit of the Hubbard model. In one dimension, phase separation takes place below a critical value αc = 0.36-0.63 which depends on the electron density. Spin gap opens in the whole region except the phase-separated one. For α ≳ 1.2 and low hole densities, charge-density-wave correlations are the most dominant, whereas singlet-pairing correlations are the most dominant in the remaining region. The possibility of superconductivity in the two-dimensional case is also discussed, based on equal-time pairing correlations.
KW - A. Superconductors
KW - D. Phase transitions
KW - D. Superconductivity
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U2 - 10.1016/S0022-3697(02)00037-9
DO - 10.1016/S0022-3697(02)00037-9
M3 - Article
AN - SCOPUS:0036602181
VL - 63
SP - 1531
EP - 1535
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
SN - 0022-3697
IS - 6-8
ER -