Related papers: Frustrated 3-Dimensional Quantum Spin Liquid in Cu…
We study the S=1/2 Heisenberg antiferromagnet on the pyrochlore lattice in the limit of strong easy-axis exchange anisotropy. We find, using only standard techniques of degenerate perturbation theory, that the model has a U(1) gauge…
We report the neutron scattering results on magnetic orderings and excitations in $\mathrm{Ba}_2\mathrm{CoTeO}_6$ composed of two almost isolated subsystems A and B, which are described as an $S\,{=}\,1/2$ triangular Heisenberg-like…
While the enhancement of the spin-space symmetry from the usual $\mathrm{SU}(2)$ to $\mathrm{SU}(N)$ is promising for finding nontrivial quantum spin liquids, its realization in magnetic materials remains challenging. Here we propose a new…
Spin liquids occuring in 2D frustrated spin systems were initially assumed to appear at strongest frustration, but evidence grows that they more likely intervene at transitions between two different types of order. To identify if this is…
121/123Sb nuclear quadrupole resonance and muon spin relaxation experiments of Mo3Sb7 revealed symmetry breakdown to a nonmagnetic state below the transition recently found at TS=50 K. The transition is characterized by a distinct lattice…
Inelastic neutron scattering measurements are reported for a powder sample of the spin-1/2 quantum paramagnet $\rm Cu(Quinoxaline)Br_2$. Magnetic neutron scattering is identified above an energy gap of 1.9 meV. Analysis of the sharp…
The quantum pyrochlore antiferromagnet is studied by perturbative expansions and exact diagonalization of small clusters. We find that the ground state is a spin-liquid state: The spin-spin correlation functions decay exponentially with…
We provide an exact study of dynamical correlations for the quantum spin-orbital liquid phases of an SU(2)-symmetric Kitaev honeycomb lattice model. We show that the spin dynamics in this Kugel-Khomskii type model is exactly the…
The search for elementary excitations with fractional quantum numbers is a central challenge in modern condensed matter physics. We explore the possibility in a realistic model for several materials, the spin-1/2 spatially anisotropic…
Motivated by recent experiments on low-dimensional quantum magnets in applied magnetic fields, we present a theoretical analysis of their properties based on the nonlinear sigma model. The spin stiffness and a 1/N expansion are used to map…
We have studied the static and dynamic magnetic properties of two-dimensional (2D) and quasi-two-dimensional, spin-S, quantum Heisenberg antiferromagnets (QHAF) diluted with spinless vacancies. Using spin-wave theory and T-matrix…
We use series expansion methods to study ground- and excited-state properties in the helically ordered phase of spin-1/2 frustrated antiferromagnets on an anisotropic triangular lattice. We calculate the ground state energy, ordering…
For nearly three decades frustrated magnetism research in three dimensions (3D) has centered on the pyrochlore geometry of corner-sharing tetrahedra and the classical spin liquid (CSL) known as spin ice. In this work, we propose that a…
Nearest-neighbor spin correlations are considered near the surface of a semi-infinite spin-$\frac12$ Heisenberg antiferromagnet on a simple cubic lattice. In the spin-wave approximation, the excitation spectrum of this model involves bulk…
We demonstrate that the insulating one-band Hubbard model on the pyrochlore lattice contains, for realistic parameters, an extended quantum spin-liquid phase. This is a three-dimensional spin liquid formed from a highly degenerate manifold…
We report the crystal growth and structural and magnetic properties of quasi two-dimensional $S=1/2$ quantum magnet Cu[C$_6$H$_2$(COO)$_4$][H$_3$N-(CH$_2$)$_2$-NH$_3$]$\cdot$3H$_2$O. It is found to crystallize in a monoclinic structure with…
A continuum of magnetic states has been observed by neutron scattering from the spin-1 chain compound CsNiCl3 in its disordered gapped one-dimensional phase. Results using both triple-axis and time-of-flight spectrometers show that around…
Spin liquids are highly correlated yet disordered states formed by the entanglement of magnetic dipoles$^1$. Theories typically define such states using gauge fields and deconfined quasiparticle excitations that emerge from a simple rule…
We report magnetization, nuclear magnetic resonance (NMR), nuclear quadrupole resonance (NQR), and transmission electron microscopy (TEM) studies on the quasi-two-dimensional spin-gap system (CuCl)LaNb2O7, a possible candidate for the J1-J2…
We report inelastic neutron scattering study of a quasi-two-dimensional S=1/2 dimer system Piperazinium Hexachlorodicuprate under hydrostatic pressure. The spin gap {\Delta} becomes softened with the increase of the hydrostatic pressure up…