The magnetic phase diagram of the quasi one-dimensional spinchain system CsNiF 3 below the Néel temperature is determined. For magnetic fields perpendicular to the spin chains incommensurate phases are predicted. From linear spin-wave theory we obtain the instability line of the paramagnetic phase as a function of the strength and the direction of the field. The system undergoes a transition to...

Example 1. Let G be a finite group. Then the set of all subgroups of G, partially ordered by inclusion, is a lattice. For H ≤ G the sublattice OG(H) of overgroups of H in G is the interval sublattice [H,G]. Call such a lattice a finite group interval lattice. There is a well-known open question as to whether every nonempty finite lattice is isomorphic to a finite group interval lattice. See [PP...

(BEDT-TTF)4Hg2.89Br8 (BEDT-TTF ) bisethylene dithiotetrathiofulvalene) is an ambient pressure low-temperature superconductor (Tc ) 4.3K) with an incommensurate two-sublattice structure. It crystallizes in orthorhombic and monoclinic modifications. Only the monoclinic phase becomes superconducting on cooling, as confirmed in this study. Its Hg sublattice undergoes a transition when the temperatu...

This review discusses the ultrafast magnetization dynamics within gigahertz to terahertz frequency range in ferrimagnetic rare-earth iron garnets with different substitutions. In these garnets, roles of spin–orbit and exchange interactions have been detected using femtosecond laser pulses via inverse Faraday effect. The all-optical control spin-wave Kaplan–Kittel resonance modes ranges is shown...