arXiv:2405.15848 · SciPost Physics
Integrable models on Rydberg atom chains
Luke Corcoran, Marius de Leeuw, Balázs Pozsgay
Abstract
We initiate a systematic study of integrable models for spin chains with constrained Hilbert spaces; we focus on spin-1/2 chains with the Rydberg constraint. We extend earlier results for medium-range spin chains to the constrained Hilbert space, and formulate an integrability condition. This enables us to construct new integrable models with fixed interaction ranges. We classify all time- and space-reflection symmetric integrable Rydberg-constrained Hamiltonians of range 3 and 4. At range 3, we find a single family of integrable Hamiltonians: the so-called RSOS quantum chains, which are related to the well-known RSOS models of Andrews, Baxter, and Forrester. At range 4 we find two families of models, the first of which is the constrained XXZ model. We also find a new family of models depending on a single coupling z z . We provide evidence of two critical points related to the golden ratio \phi ϕ , at z=\phi^{-1/2} z = ϕ − 1 / 2 and z=\phi^{3/2} z = ϕ 3 / 2 . We also perform a partial classification of integrable Hamiltonians for range 5.