Emergent orbital dynamics in strongly spin-orbit coupled systems
Phys. Rev. B 113, 035105 – Published 2 January, 2026
DOI: https://doi.org/10.1103/639b-9j61
Abstract
The interplay between spin and orbital degrees of freedom gives rise to a variety of emergent phases in correlated and transition-metal systems. Among these materials, it is known that strong spin–orbit coupling (SOC) significantly alters Jahn-Teller (JT) effects, either by suppressing static distortions or promoting dynamic fluctuations, so that orbital polarization related to JT effects is reduced or even quenched. Here, by using a Matsubara lattice formalism, we investigate how orbital fluctuations are generated and propagated by local perturbations in spin-orbit coupled systems with no global polarization, corresponding to either orbitally disordered phases or dynamic JT regimes. By analyzing how such perturbations propagate through the correlated, spin-orbit-entangled ground state, we observe that they generate short-range orbital fluctuations that carry local polarization. We find that these dynamical fluctuations propagate to neighboring sites with a polarization orthogonal to the initial perturbation. Finally, we discuss to what extent such orbital fluctuations may be probed as excitations in spectroscopic measurements.