Doping asymmetry in the three-band Hamiltonian for cuprate ladders: failure of the standard model of superconductivity in cuprates

TL;DR

This paper uses DMRG calculations on a three-band model for cuprate ladders to reveal doping asymmetry, challenging the standard single-band model's ability to explain superconductivity symmetry in cuprates.

Contribution

It demonstrates that the three-band Hamiltonian exhibits doping asymmetry, indicating limitations of the standard model in capturing cuprate superconductivity.

Findings

Strong doping asymmetry observed in the three-band model.

Contradicts the assumed symmetry between electron- and hole-doped cuprates.

Questions the adequacy of the single-band Hubbard model for cuprate superconductivity.

Abstract

The relevance of the single-band two-dimensional Hubbard model to superconductivity in the doped cuprates has recently been questioned, based on Density matrix Renormalization Group (DMRG) computations on extended t-J models that found superconductivity over unrealistically broad doping region upon electron-doping, yet complete absence of superconductivity for hole-doping. We report very similar results from DMRG calculations on Cu$_2$O$_3$ two-leg ladder within the parent three-band correlated-electron Hamiltonian. The strong asymmetry found in our calculations are in contradiction to the deep and profound symmetry between electron- and hole-doped cuprate superconductors, apart from their critical temperatures, that has been found from recent experiments.