Exactly solvable quantum spin tubes and ladders

TL;DR

This paper introduces exactly solvable models of quantum spin tubes and ladders with arbitrary interactions, mapped to su(N) spin chains, and solved using nested Bethe Ansatz, advancing understanding of integrable quantum spin systems.

Contribution

It presents new integrable models of n-leg spin-1/2 ladders and tubes with arbitrary interactions, solved via nested Bethe Ansatz, extending the class of exactly solvable quantum spin systems.

Findings

Models are equivalent to su(N) spin chains with N=2^n.

Arbitrary rung interactions induce chemical potentials in the equivalent chains.

Models are solvable by nested Bethe Ansatz.

Abstract

We find families of integrable n-leg spin-1/2 ladders and tubes with general isotropic exchange interactions between spins. These models are equivalent to su(N) spin chains with N=2^n. Arbitrary rung interactions in the spin tubes and ladders induce chemical potentials in the equivalent spin chains. The potentials are n-dependent and differ for the tube and ladder models. The models are solvable by means of nested Bethe Ansatz.