Twisted Quantum Affine Superalgebra $U_q[sl(2|2)^{(2)}]$, $U_q[osp(2|2)]$ Invariant R-matrices and a New Integrable Electronic Model

TL;DR

This paper explores the structure of twisted quantum affine superalgebras, derives invariant R-matrices, and introduces a new integrable electronic model with potential applications in strongly correlated systems.

Contribution

It explicitly decomposes tensor products of representations of twisted superalgebras and constructs a novel integrable electronic model based on these algebraic structures.

Findings

Derived two $U_q[osp(2|2)]$ invariant R-matrices.

Constructed a new integrable electronic model.

Model reduces to known $sl(2|2)$ symmetric model at $q=1$.

Abstract

We describe the twisted affine superalgebra $sl(2|2)^{(2)}$ and its quantized version $U_q[sl(2|2)^{(2)}]$. We investigate the tensor product representation of the 4-dimensional grade star representation for the fixed point subsuperalgebra $U_q[osp(2|2)]$. We work out the tensor product decomposition explicitly and find the decomposition is not completely reducible. Associated with this 4-dimensional grade star representation we derive two $U_q[osp(2|2)]$ invariant R-matrices: one of them corresponds to $U_q[sl(2|2)^{(2)}]$ and the other to $U_q[osp(2|2)^{(1)}]$. Using the R-matrix for $U_q[sl(2|2)^{(2)}]$, we construct a new $U_q[osp(2|2)]$ invariant strongly correlated electronic model, which is integrable in one dimension. Interestingly, this model reduces, in the $q=1$ limit, to the one proposed by Essler et al which has a larger, $sl(2|2)$, symmetry.