Spin dynamics of the block orbital-selective Mott phase
Abstract
Iron-based superconductors display a variety of magnetic phases originating in the competition between electronic, orbital, and spin degrees of freedom. Previous theoretical investigations of the multi-orbital Hubbard model in one dimension revealed the existence of an orbital-selective Mott phase (OSMP) with block spin order. Recent inelastic neutron scattering (INS) experiments on the BaFeSe ladder compound confirmed the relevance of the block-OSMP. Moreover, the powder INS spectrum reveled an unexpected structure, containing both low-energy acoustic and high-energy optical modes. Here we present the theoretical prediction for the dynamical spin structure factor within a block-OSMP regime using the density-matrix renormalization group method. In agreement with experiments we find two dominant features: low-energy dispersive and high-energy dispersionless modes. We argue that the former represents the spin-wave-like dynamics of the block ferromagnetic islands, while the latter is attributed to a novel type of local on-site spin excitations controlled by the Hund coupling.
Cite
@article{arxiv.1804.01959,
title = {Spin dynamics of the block orbital-selective Mott phase},
author = {J. Herbrych and N. Kaushal and A. Nocera and G. Alvarez and A. Moreo and E. Dagotto},
journal= {arXiv preprint arXiv:1804.01959},
year = {2021}
}