Ground-state and spectral properties of the doped one-dimensional optical Hubbard-Su-Schrieffer-Heeger model

We present a density matrix renormalization group study of the doped one-dimensional (1D) Hubbard-Su-Schrieffer-Heeger (Hubbard-SSH) model, where atomic displacements linearly modulate nearest-neighbor hopping integrals. Focusing on an optical variant model in strongly correlated limit relevant for cuprate spin chains, we examine how SSH interaction modifies model's ground- and excited-state properties. The coupling weakly renormalizes single- two-particle response functions electron-phonon $(e\text{\ensuremath{-}}\mathrm{ph})$ strengths below parameter-dependent critical value ${g}_{\mathrm{c}}$. For larger $e\text{\ensuremath{-}}\mathrm{ph}$ coupling, sign effective integrals changes subset orbitals, which drives lattice dimerization distinct from standard nesting-driven picture 1D. spectral weight one- dynamical are dramatically rearranged across this transition, with significant ground-state correlations. argue that results breakdown linear approximation thus signals fundamental limitation interaction. Our have consequences our understanding SSH-like interactions can enter physics quantum materials, including recently synthesized chains.