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Phase separation and the existence of superconductivity in a one-dimensional copper-oxygen model

A. W. Sandvik·A. Sudbo
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Abstract

The phase separation instability occurring with increasing nearest-neighbor repulsion V in a two-band Hubbard model (CuO chain) is discussed. Quantum Monte Carlo simulations indicate that this transition is associated with a level-crossing if the filling fraction is close to 1 (half-filled lower band). Spin-density-wave fluctuations then dominate before phase separation. Superconducting fluctuations dominate only at considerably higher doping levels.

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A. W. Sandvik, A. Sudbo. 1996-03-11. Phase separation and the existence of superconductivity in a one-dimensional copper-oxygen model. https://doi.org/10.1103/physrevb.54.r3746

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