2025/08/11 by Prokopczyk, J., Herbrych, J.
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2508.07712
Antiferromagnetic ground states, when doped, give rise to rich and complex phenomena, prompting detailed investigations in various spin systems. Here, we study the effect of doping on the one-dimensional S = 1 antiferromagnetic Heisenberg model (AFM). Specifically, we investigate how the presence of holes affects the static and dynamic (frequency-dependent) spin-spin correlations of the two-orbital Hubbard-Kanamori chain. The latter, at half-filling and in the limit of strong interactions, maps onto an S = 1 Heisenberg model. For moderate interactions, an orbital resonating-valence-bond (orbital-RVB) state emerges up to doping levels of x \lesssim 0.4. A detailed analysis of interaction strength U and doping concentration x reveals that this phase inherits the key features of spin excitations found in the half-filled case -- namely, a gapped spin spectrum and ``coherent'' magnon behavior up to a wavevector q determined by the Fermi vector, 2kF = π(1 - x). Furthermore, our results uncover an additional broad, incoherent spectral weight for q \gtrsim 2kF at high frequencies. Finally, we show that near the transition to a ferromagnetic phase, a previously unidentified spiral-like state emerges, characterized by spin excitations reminiscent of the J1-J2 Heisenberg model.