Spin-Dependent Excitations

Spin excitations in ferromagnetic manganites

An effective one–band Hamiltonian for colossal–magnetoresistance (CMR) manganites is constructed and the spin excitations are determined. Fitting the experimental data by the derived spin–wave dispersion gives an eg–electron hopping amplitude of about 0.2 eV in agreement with LDA band calculations.

Helimagnon Bands as Universal Spin Excitations

Spin Excitations in Localized and Itinerant Magnets

Collective excitations in magnetic materials can be investigated by means of inelastic neutron scattering. We show that this experimental method gives access to the complete spectrum of magnetic fluctuations through the energyand momentum-dependence of the dynamical susceptibility. We focus on the dynamical properties of magnets with localized spin densities and of metals. From such studies, mi...

Electromagnon excitations in canted-spin multiferroics

Elementary excitations in gapped quantum spin systems.

For quantum lattice systems with local interactions, the Lieb-Robinson bound serves as an alternative for the strict causality of relativistic systems and allows the proof of many interesting results, in particular, when the energy spectrum exhibits an energy gap. In this Letter, we show that for translation invariant systems, simultaneous eigenstates of energy and momentum with an eigenvalue t...