DMRG study of the spin gap in a one dimensional Hubbard model: effect of the distant transfer and exchange coupling

Ryotaro Arita; Kazuhiko Kuroki; Hideo Aoki; Michele Fabrizio

doi:10.1103/physrevb.57.10324

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DMRG study of the spin gap in a one dimensional Hubbard model: effect of the distant transfer and exchange coupling

Ryotaro Arita·Kazuhiko Kuroki·Hideo Aoki·Michele Fabrizio

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Abstract

The spin gap of a one-dimensional repulsive Hubbard model is numerically calculated with the density matrix renormalization group, with a special emphasis on the effect of a next-nearest neighbor hopping (t') and the nearest-neighbor ferromagnetic exchange (J) interaction. At half-filling, a significant spin gap opens if |t'| \simeq |t| and J=0, in agreement with the weak coupling theory, while the gap is strongly suppressed by the introduction of J. On the other hand, the quarter-filled system has very small spin gaps regardless of the values of t' and J. Implications for the CuO_2 chain in Sr_{14}Cu_{24}O_{41} and related materials are discussed.

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Ryotaro Arita, Kazuhiko Kuroki, Hideo Aoki, Michele Fabrizio. 1997-12-12. DMRG study of the spin gap in a one dimensional Hubbard model: effect of the distant transfer and exchange coupling. https://doi.org/10.1103/physrevb.57.10324

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