相关论文: Orbital and spin chains in ZnV2O4
The thermal equilibrium properties of the spin-ice material DTO, including specific heat, magnetization, and spin correlations, could be successfully reproduced by a model featuring magnetic interactions up to the third nearest neighbor and…
We have synthesized single-crystal samples of $\beta$-VOSO$_4$ and fully characterized their magnetic properties. Our magnetic susceptibility, high field magnetization and powder inelastic neutron scattering results are in excellent…
Na$_{4-\delta}$NiTeO$_{6}$ is a rare example in the transition-metal tellurate family of realizing an $S$ = 1 spin-chain structure. By performing neutron powder diffraction measurements, the ground-state magnetic structure of…
We report the magnetic excitation spectrum as measured by inelastic neutron scattering for a polycrystalline sample of Sr$_3$CuPtO$_6$. Modeling the data by the 2+4 spinon contributions to the dynamical susceptibility within the chains, and…
We study the exchange constants of MnV$_2$O$_4$ using magnetic force theorem and local spin density approximation of density functional theory supplemented with a correction due to on-site Hubbard interaction U. We obtain the exchanges for…
We obtain the ground-state phase diagram of two spin chains consisting in a set two-level systems asymmetrically coupled to an XX chain through a chiral interaction. The interaction is parametrized by its magnitude and an angle defined by…
Neutron spectroscopy has revealed a highly unusual magnetic structure and dynamics in YVO$_3$, an insulating pseudocubic perovskite that undergoes a series of temperature induced phase transitions between states with different spin and…
Motivated by recent experiments on quasi-1D vanadium oxides, we study quantum phase transitions in a one-dimensional spin-orbital model describing a Haldane chain and a classical Ising chain locally coupled by the relativistic spin-orbit…
We report the results of elastic neutron scattering measurements performed on 1/8-hole doped La$_{1.875}$Ba$_{0.125-x}$Sr$_{x}$CuO$_{4}$ single crystals with {\it x}=0.05, 0.06, 0.075 and 0.085. In the low-temperature less-orthorhombic…
The structure and magnetic properties of Mn1+xV2-xO4 (0<x<=1), a complex frustrated system, were investigated by heat capacity, magnetization, x-ray diffraction, and neutron diffraction measurements. For x<=0.3, a cubic-to-tetragonal (c >…
Recent state-of-the-art crystallographic investigations of transition metal spinel compounds have revealed that the d- orbital charge carriers undergo ordering transitions with the formation of local "molecular bonding" units such as dimers…
Single crystals of the heavy-fermion compound YbAgGe have been studied by neutron scattering. The magnetic ordering occurring below T1=0.5 K is characterized by a commensurate propagation vector k=(1/3,0,1/3) and the moments in the basal…
Low-frequency spin dynamics in the S=1/2 antiferromagnetic spin-chain compound \alpha-VO(PO_3)_2 has been studied by means of 31P NMR. The nuclear spin-lattice relaxation rate 1/T_1 at the P site exhibits H^{-1/2} dependence on the applied…
The spinel vanadates have become a model family for exploring orbital order on the frustrated pyrochlore lattice, and recent debate has focused on the symmetry of local crystal fields at the cation sites. Here, we present neutron scattering…
The alloy Ca$_{2-x}$Sr$_x$RuO$_4$ exhibits a complex phase diagram with peculiar magnetic metallic phases. In this paper some aspects of this alloy are discussed based on a mean field theory for an effective Kugel-Khomskii model of…
Below about 150 K, the spin arrangement in the chain arrays of Sr14Cu24O41 is shown to develop in two dimensions (2D). Both the correlations and the dispersion of the observed elementary excitations agree well with a model of interacting…
The magnetic susceptibility and magnetization of high quality single crystal beta-TeVO4 are reported. We show that this compound, made of weakly coupled infinite chains of VO5 pyramids sharing corners, behaves as a S = 1/2 one-dimensional…
We use exact diagonalization combined with mean-field theory to investigate the phase diagram of the spin-orbital model for cubic vanadates. The spin-orbit coupling competes with Hund's exchange and triggers a novel phase, with the ordering…
We report single-crystal neutron diffraction studies on a spinel antiferromagnet GeCo$_2$O$_4$, which exhibits magnetic order with a trigonal propagation vector and tetragonal lattice expansion ($c/a\simeq1.001$) below $T_{\rm N}=21$ K. For…
Electronic instabilities in transition metal compounds often spontaneously form orbital molecules, which consist of orbital-coupled metal ions at low temperature. Recent local structural studies utilizing the pair distribution function…