Exact spontaneous plaquette ground states for high-spin ladder models

TL;DR

This paper rigorously proves the existence of a spontaneous plaquette ground state in a high-spin ladder model, revealing strong quantum fluctuations and fractionalized excitations, with implications for ultracold atomic systems.

Contribution

It introduces a new exactly solvable model demonstrating a plaquette ground state in high-spin ladder systems with SU(N) symmetry.

Findings

Existence of a spontaneous plaquette ground state without spin order.

Topological excitations exhibit fractionalization.

Generalization to SU(N) systems explored.

Abstract

We study the exchange physics in high spin Mott insulating systems with $S=3/2$ which is realizable in ultracold atomic systems. The high symmetry of SO(5) or SU(4) therein renders stronger quantum fluctuations than the usual spin-1/2 systems. A spontaneous plaquette ground state without any site and bond spin orders is rigorously proved in a ladder spin-3/2 model, whose topological excitations exhibit fractionalization behavior. The generalization to the SU(N) plaquette state is also investigated.