Antiferromagnetic and van Hove Scenarios for the Cuprates: Taking the Best of Both Worlds

TL;DR

This paper proposes a theory for high-temperature superconductivity in cuprates, combining antiferromagnetic correlations and van Hove singularities, successfully reproducing several experimental observations.

Contribution

It introduces an effective Hamiltonian derived from the 2D t-J model that explains superconductivity and related phenomena without free parameters.

Findings

Superconductivity in the d_{x^2-y^2} channel with T_c ~ 100K at optimal doping.

Reproduction of experimental van Hove singularities from AF correlations.

Quasiparticle lifetime linearly dependent on energy.

Abstract

A theory for the high temperature superconductors is proposed. Holes are spin-1/2, charge e, quasiparticles strongly dressed by spin fluctuations. Based on their dispersion, it is claimed that the experimentally observed van Hove singularities of the cuprates are likely originated by antiferromagnetic (AF) correlations. From the two carriers problem in the 2D t-J model, an effective Hamiltonian for holes is defined with %no free parameters. This effective model has superconductivity in the ${\rm d_{x^2-y^2}}$ channel, a critical temperature ${\rm T_c \sim 100K}$ at the optimal hole density, ${\rm x=0.15}$, and a quasiparticle lifetime linearly dependent with energy. Other experimental results are also $quantitatively$ reproduced by the theory.