Abstract
The model is a standard model of strongly correlated electrons, often studied in the context of high- superconductivity. However, most studies of this model neglect three-site terms, which appear at the same order as the superexchange . As these terms correspond to pair hopping, they are expected to play an important role in the physics of superconductivity when doped sufficiently far from half filling. We present a density matrix renormalization-group study of the one-dimensional model with the pair hopping terms included. We demonstrate that these additional terms radically change the one-dimensional ground-state phase diagram, extending the superconducting region at low fillings, while at larger fillings, superconductivity is completely suppressed. We explain this effect by introducing a simplified effective model of repulsive hardcore bosons.
- Received 27 April 2018
- Revised 28 June 2018
DOI:https://doi.org/10.1103/PhysRevB.98.035116
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