New Exactly Solvable Model of Strongly Correlated Electrons Motivated by High T_c Superconductivity

TL;DR

This paper introduces a new exactly solvable model for strongly correlated electrons on a lattice, incorporating local electron pairs and potential relevance to high-temperature superconductivity.

Contribution

It presents a novel lattice model that generalizes the Hubbard and t-J models, featuring exact solutions and mechanisms for electron pairing.

Findings

Model includes local electron pairs that move coherently.

Eigenstates with off-diagonal long-range order are constructed.

Model is exactly solvable in one dimension via Bethe Ansatz.

Abstract

We present a new model describing strongly correlated electrons on a general $d$-dimensional lattice. It differs from the Hubbard model by interactions of nearest neighbours, and it contains the $t$-$J$ model as a special case. The model naturally describes local electron pairs, which can move coherently at arbitrary momentum. By using an $\eta$-pairing mechanism we can construct eigenstates of the hamiltonian with off-diagonal-long-range-order (ODLRO). These might help to relate the model to high-$T_c$ superconductivity. On a one-dimensional lattice, the model is exactly solvable by Bethe Ansatz.