Dimerization in α-TiCland α-TiBr: the DFT study.

A series of DFT calculations for two layered compounds with honeycomb lattice-α-TiCland α-TiBrhas been performed. It was shown that the symmetric SU(4) spin-orbital model recently proposed forsystems with honeycomb lattice cannot be realized in these titanates because they dimerize in the low temperature phase. This explains experimentally observed drop in magnetic susceptibility of α-TiBr.

Quasi-1D XY antiferromagnet SrNi(SeO)Cl at Sakai-Takahashi phase diagram.

Uniform quasi-one-dimensional integer spin compounds are of interest as a potential realization of the Haldane conjecture of a gapped spin liquid. This phase, however, has to compete with magnetic anisotropy and long-range ordered phases, the implementation of which depends on the ratio of interchain J' and intrachain J exchange interactions and both uniaxial D and rhombic E single-ion anisotropies. Strontium nickel selenite chloride, SrNi(SeO)Cl, is a spin-1 chain system which passes through a correlations regime at T ~ 12 K to long-range order at T = 6 K.

Kerr-lens mode-locked Cr:ZnS oscillator reaches the spectral span of an optical octave.

We report, to the best of our knowledge, the first super-octave femtosecond polycrystalline Cr:ZnS laser at the central wavelength 2.4 µm. The laser is based on a non-polarizing astigmatic X-folded resonator with normal incidence mounting of the gain element.

Middle-IR frequency comb based on Cr:ZnS laser.

We report, to the best of our knowledge, the first fully referenced Cr:ZnS optical frequency comb. The comb features few cycle output pulses with 3.25 W average power at 80 MHz repetition rate, spectrum spanning 60 THz in the middle-IR range 1.

Multi-octave visible to long-wave IR femtosecond continuum generated in Cr:ZnS-GaSe tandem.

We report a technique for generation of broad and coherent femtosecond (fs) continua that span several octaves from visible to long-wave IR parts of the spectrum (0.4-18 µm). The approach is based on simultaneous amplification of few-cycle pulses at 2.