Related papers: Spin-lattice instability to a fractional magnetiza…
We report low-temperature powder X-ray and neutron diffraction studies on breathing pyrochlore magnets Cu$M$Cr$_{4}$S$_{8}$ ($M$ = Al, Ga), which undergo a magnetic transition at $T_{\rm N} \approx$ 21 and 31 K for {$M$ = Al and Ga,…
We performed small-angle neutron scattering (SANS) measurements on the helimagnetic spinel compound ZnCr2Se4. The ground state of this material is a multi-domain spin-spiral phase, which undergoes domain selection in a magnetic field and…
Motivated by recent experiments on the frustrated quantum magnetic compound YbMgGaO4, we study an effective spin model on triangular lattice taking into account the effects of the spin-orbit coupling. We determine the classical ground-state…
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…
Thermodynamic experiments as well as Raman scattering have been used to study the magnetic instabilities in the spin-tetrahedra systems Cu_2Te_2O_5X_2, X=Cl and Br. While the phase transition observed in the Cl system at T_o=18.2 K is…
By means of neutron scattering techniques we have investigated the frustrated pyrochlore magnet Ho_2Sn_2O_7, which was found to show a ferromagnetic spin-ice behavior below T \simeq 1.4 K by susceptibility measurements. High-resolution…
We report the magnetic properties of $A$-site spinel compound MnSc$_2$Se$_4$. The macroscopic magnetic measurements uncovers successive magnetic transitions at $T_{\rm{N1}}$= 2.04 K, followed by two further transitions at $T_{\rm{N2}}$=1.8…
We study the ground state phase diagram of a frustrated spin-1/2 four-leg spin tube in an external magnetic field. We explore the parameter space of this model in the regime of all-antiferromagnetic exchange couplings by means of three…
We report detailed measurements of the low temperature magnetic phase diagram of Er$_2$Ti$_2$O$_7$. Heat capacity and time-of-flight neutron scattering studies of single crystals, subject to magnetic fields applied along the…
We analyzed the magnetic susceptibilities of several Cr spinels using two recent models for the geometrically frustrated pyrochlore lattice, the Quantum Tetrahedral Mean Field model and a Generalized Constant Coupling model. Both models can…
The chromium spinels MgCr2O4 and ZnCr2O4 are prime examples of the highly frustrated pyrochlore lattice antiferromagnet. Experiment has carefully established that both materials, upon cooling, distort to lower symmetry and order…
We demonstrate the existence of a spin-nematic, moment-free phase in a quantum four-spin ring exchange model on the square lattice. This unusual quantum state is created by the interplay of frustration and quantum fluctuations which lead to…
We study theoretically the lattice instability in the spin gap systems under magnetic field. With the magnetic field larger than a critical value h_{c1}, the spin gap is collapsed and the magnetization arises. We found that the lattice…
Magnetic pyrochlore oxides, including the spin ice materials, have proved to be a rich field for the study of geometrical frustration in 3 dimensions. Recently, a new family of magnetic oxides has been synthesised in which the half of the…
High-resolution ac susceptibility and thermal conductivity measurement on Cu2Te2O5X2(X=Br,Cl) single crystals are reported. For Br-sample, sample dependence prevents to distinguish between possibilities of magnetically ordered and…
We have investigated spin-wave excitations in a four-sublattice (4SL) magnetic ground state of a frustrated magnet CuFeO2, in which `electromagnon' (electric-field-active magnon) excitation has been discovered by recent terahertz…
The existance of a spin disordered ground state for the frustrated Quantum Heisenberg Antiferromagnet on a square lattice is reconsidered. It is argued that there is a unique action which is continuous through the whole phase diagram,…
We study a spin system with two- and four-spin exchange interactions on the triangular lattice, which is a possible model for the nuclear magnetism of solid $^3$He layers. It is found that a novel spin structure with scalar chiral order…
CoAl2O4 spinel with magnetic Co2+ ions on the diamond A-lattice is known to be magnetically frustrated. We compare neutron single crystal diffraction patterns measured in zero and applied magnetic fields with the ones obtained from…
The magnetization processes of the spin-3/2 antiferromagnet LiInCr4O8 comprising a "breathing" pyrochlore lattice, which is an alternating array of small and large tetrahedra, are studied under ultrahigh magnetic fields of up to 130 T using…