Unraveling higher-order corrections in the spin dynamics of RIXS spectra

Abstract

Resonant inelastic x-ray scattering (RIXS) is an evolving tool for investigating spin dynamics of strongly correlated materials, which complements inelastic neutron scattering. Both techniques have found that non-spin-conserving (NSC) excitations in quasi-1D isotropic quantum antiferromagnets are confined to the two-spinon phase space. Outside this phase space, only spin-conserving (SC) four-spinon excitations have been detected using O $K$-edge RIXS. Here, we investigate SrCuO${}_2$ and find four-spinon excitations outside the two-spinon phase space at both O $K$- and Cu $L_3$-edges. Using the Kramers-Heisenberg formalism, we demonstrate that the four-spinon excitations arise from both SC and NSC processes at Cu $L_3$-edge. We show that these new excitations only appear in the second-order terms of the ultra-fast core-hole lifetime expansion and arise from long-range spin fluctuations. These results thus open a new window to the spin dynamics of quantum magnets.

10 pages, 4+3 figures

References in corpus (12)

• Spin-Orbital Separation in the quasi 1D Mott-insulator Sr2CuO3
• Anomalous High-Energy Spin Excitations in La2CuO4
• Spin excitations in a single La${}_2$CuO${}_4$ layer
• Observation of a 500meV Collective Mode in La${}_{2-x}$Sr${}_x$CuO${}_4$ and Nd${}_2$CuO${}_4$
• Ultrashort Lifetime Expansion for Indirect Resonant Inelastic X-ray Scattering
• Polarization resolved Cu $L_3$-edge resonant inelastic x-ray scattering of orbital and spin excitations in NdBa${}_2$Cu${}_3$O${}_{7-\delta }$
• Multiple-magnon excitations shape the spin spectrum of cuprate parent compounds
• Quadrupolar magnetic excitations in an isotropic spin-1 antiferromagnet
• Particle-hole asymmetry in the dynamical spin and charge structure factors of the corner-shared one-dimensional cuprates
• Theoretical study of the spin and charge dynamics of two-leg ladders as probed by resonant inelastic x-ray scattering
• Mobile orbitons in Ca${}_2$CuO${}_3$: crucial role of the Hund's exchange
• Non-perturbative series expansion of Green's functions: The Anatomy of Resonant Inelastic X-Ray Scattering in Doped Hubbard Model

Cited by in corpus (8)

• Exploring Quantum Materials with Resonant Inelastic X-Ray Scattering
• Emergence of spinons in layered trimer iridate Ba4Ir3O10
• Crossover of the high-energy spin fluctuations from collective triplons to localized magnetic excitations in doped Sr14-xCaxCu24O41 cuprate ladders
• Theory of electron-phonon interactions in extended correlated systems probed by resonant inelastic x-ray scattering
• Softening of $dd$ excitation in the resonant inelastic x-ray scattering spectra as a signature of Hund's coupling in nickelates
• Theoretical analysis of multi-magnon excitations in resonant inelastic x-ray scattering spectra of two-dimensional antiferromagnets
• Observation of spin-conserving two-spinon continuum in the $S$=1/2 antiferromagnetic chain system Sr${}_2$CuO${}_3$ using Cu $K$-edge resonant inelastic x-ray scattering
• Multimagnon and multispinon $L_3$-edge RIXS spectra of an effective ${\tilde{J}}_1-{\tilde{J}}_2-{\tilde{J}}_3$ square lattice Heisenberg model